View Full Version : Backfire at Startup!!!!!!


g21-30
March 11th, 2009, 04:33 PM
I haven't been able to ride since Sunday, so I finally hurried out just before sundown tonight. It was 64 degrees F. Turn the ignition on and barely moved the choke. Hit the start button and BANG! :eek: Almost jumped off the bike. Let me tell you, normally nothing makes me jump, but my "virtual" behind was already sitting on top of my wife's Jeep Wrangler (parked in front of me).

Yes, my friend, I read everyone of the threads at the kawi forum about this. Just wanted to share my experience with everyone. Almost 700 miles on the bike and made it thru the winter without this occuring. I will be expecting it next time.

kkim
March 11th, 2009, 04:34 PM
:D

athimmel
March 11th, 2009, 04:40 PM
Tell you one thing...if it happens at 7 am, it will wake you up.

It will wake you, your wife, your neighbors, people in China...

Sailariel
March 11th, 2009, 04:50 PM
They seem to do that on ocassion--really don`t know why--but they do. I sort of like to think that Kermit is clearing his throat.

Viper-Byte
March 11th, 2009, 04:52 PM
Mine will occasionally backfire at startup. I am actually trying to replicate it so I can find the cause.

I played with the throttle when it was off lastnight and this morning before starting and no backfire...

Rynownd
March 12th, 2009, 08:32 AM
First time I heard it, my bike was backed up to my house, so the pipe was opening about 3ft from a wall.
...had to change my pants after that one.

aloh
March 12th, 2009, 06:07 PM
it happened to me again today for the first time in months. It gave me a bit of a scare when i started it up in the garage to roll out...

TheDuck
March 12th, 2009, 09:09 PM
I get a nasty afterfire out the exhaust with a nice burst of flames! Its LOUD! It happens at least once a week when starting it from cold first thing in the morning. It scared the crap out of me the first time. Choke or not, there is no consistency to it.

One morning a bunch of gangbangers were across the street hanging out with one of the teenage boys over there when it FIRED! They all ran for cover, you'd of thought that there was a driveby going on, haha.

Just glad I didn't get shot!

paterick4o8
March 12th, 2009, 10:15 PM
Hey! This happened to me too! Gave me a fright at first. I just assumed it was because of my aftermarket slip on not installed properly since it was a DIY for me.

I always cover my hear when I start it up now but it hasn't happened for a while. When it was happening my pipe was about 3ft or less from the wall too, kept in an underground garage at my condo. So idk.. was it the cold in that big garage, the distance from the wall, my slip on, of all of the above? All I know is that it stopped doing it.

Reddoak
March 15th, 2009, 06:31 PM
If mine sits for more than 2 days, I kind of expect it at this point. I only get it maybe 1 time out of 5, but it's pretty damn loud... I've learned to cover one ear (the one closest to the exhaust,) especially on cooler (<70*) days.

Justanothermp5
March 15th, 2009, 07:28 PM
mine did it once, before i wrecked it :(
but yea i didnt even notice it till my mom was like, wtf was that lol

it was pretty loud though, but i have a full face so i guess that deadens the sound

paterick4o8
March 17th, 2009, 09:00 PM
whaa wth?? it did it today again for me.. but it was sunny and temperature in the mid 60s outside.
last time this happened was almost 2 months ago. I don't get it

kkim
March 17th, 2009, 09:10 PM
that's the point... nobody gets it. :D

ride2max
March 18th, 2009, 12:32 AM
It happen to me yesterday when i try to start my bike, suddenly a cannon firing sound came out from my pipe after almost a week i didnt use my bike even malaysia weather is hot all day long.

komohana
March 22nd, 2009, 09:26 AM
just curious and maybe i missed the answer to this...is it happening only during start-up?

kkim
March 22nd, 2009, 09:27 AM
yes

craha
March 22nd, 2009, 12:49 PM
I have around 1200 miles on my 09 and it's happened to me twice.

komohana
March 22nd, 2009, 03:52 PM
backfire due to the sensitivity of internal transitional passages. This condition cannot be corrected." :(

i see...

so...yer bike...got hot farts is all

:confused20:

ride2max
March 23rd, 2009, 06:52 AM
Regrading with the backfire at startup, i ask few of my friends, they said maybe there some fuel still trap inside the carb. They advise is not to itchy hand try open the throttle when you want to stop the engine.

noche_caliente
March 29th, 2009, 09:19 AM
girls don't fart, remember?

sm0kediver
March 29th, 2009, 01:34 PM
Has my first backfire today. 646 miles on the bike, temperature in the mid 40s... first crank of the day and it went Bang! It wasn't like a gun. More like a small firecracker.

Nemy
March 29th, 2009, 04:30 PM
ooo my backfire devirgining was like a gun. Happened last week (500+kms). Thankfully I didn't freak out cause I remembered this thread :D

sm0kediver
March 29th, 2009, 05:19 PM
I read that thread. My personal observations:

I don't play with the throttle when it isn't running.

I crank it without the choke.

It backfired anyway.

I prefer the whistling gas tank anomaly to the exploding engine conundrum

:rolleyes:

That's all for now :D

Lurkable
April 3rd, 2009, 10:29 AM
10k miles and not a single backfire. Sometimes I wish it would happen just once so I know what everyone is talking about when they say it's "loud."

TheDuck
April 3rd, 2009, 10:40 AM
Yep, mine does both! I don't mind the whistling and I've grown to expect the BANG or the squirt like yesterday morning! :eek:

It squirted? It must really like you!

Nemy
April 3rd, 2009, 11:57 AM
10k miles and not a single backfire. Sometimes I wish it would happen just once so I know what everyone is talking about when they say it's "loud."

jeebus! Don't tell me you've got 10k on an 09 already?! :confused:

But if you've owned a pre-gen, it didn't seem to backfire on those - or atleast it never happened to me. After 500kms on the new-gen, though, I thought I got shot...

TheDuck
April 3rd, 2009, 12:59 PM
jeebus! Don't tell me you've got 10k on an 09 already?! :confused:

But if you've owned a pre-gen, it didn't seem to backfire on those - or atleast it never happened to me. After 500kms on the new-gen, though, I thought I got shot...

I still never had an actual "backfire." Its always an AFTERfire. Where the explosion occurs out the EXHAUST, not out of the carbs.

Of course this was more obvious when I upgraded to the AreaP exhaust. No baffles or flip-flopping chambers in there to contain it.

If I give it a little rev to 5k let it wind down a bit and fiddle with my run switch at a red light I can make it POP really loud scaring the other drivers around me. At night I even get a nice 24" blue flame. If I had a catalytic it would probably be harmful, otherwise it sure is fun! :thumbup:

Ramen
April 3rd, 2009, 05:06 PM
The motorcycle is irrevocably damaged. Please send it to me for proper disposal. :D

kkim
April 3rd, 2009, 05:23 PM
http://www.2carpros.com/how_does_it_work/backfire.htm

What is a Backfire?
There are typically two kinds of engine backfires, one is generated from the intake manifold of the engine, and the second is expelled from the exhaust pipe at the rear of the car. A backfire is an explosion of sorts in the intake manifold or the exhaust system. A backfire occurs when there is an imbalance in the air to fuel ratio required for your vehicle to operate properly. If the fuel mixture is too lean (not enough fuel) you may have a backfire in the intake, or too rich (too much fuel) you may get a backfire out of the exhaust system. Most backfires are easily repaired by correcting the imbalance and providing a greater or lesser percentage of fuel to the mixture.

snowlife
April 16th, 2009, 04:07 AM
http://www.2carpros.com/how_does_it_work/backfire.htm

What is a Backfire?
There are typically two kinds of engine backfires, one is generated from the intake manifold of the engine, and the second is expelled from the exhaust pipe at the rear of the car. A backfire is an explosion of sorts in the intake manifold or the exhaust system. A backfire occurs when there is an imbalance in the air to fuel ratio required for your vehicle to operate properly. If the fuel mixture is too lean (not enough fuel) you may have a backfire in the intake, or too rich (too much fuel) you may get a backfire out of the exhaust system. Most backfires are easily repaired by correcting the imbalance and providing a greater or lesser percentage of fuel to the mixture.

I agree.
My bike, (bmw f800gs) backfires in a minimal way only, but only while riding This occurs due to a slip on exhaust that has a bad seal, then you role off the throttle thus extra air gets in exhaust and you get a nice little pop pop pop. No probs, quite nice actually (this is common on this model and very much liked by many owners). One possible cause with the 250r, but very unlikely due to your exhaust construction and no movement at the time to loosen seal.

It sounds like your bikes are getting a huge bang. This is not good for the exhaust, even worse if it is in the intake. A big bang in the exhaust can destroy cats and internal parts.
To diagnose i would be looking at 1. how you turn off your bike, maybe in a way that leave excess fuel in the cylinder/carbie. 2. turning off you fuel tap so that no fuel can leak into the carbie/cylinder (assuming there is a tap).

In both cases (assumed exhaust backfire) when the engine ticks over the first few time the mix may be to rich and not ignite or just not ignite due to cold/other reasons. Result extra fuel/air mix ends in the exhaust, result, backfire.

Good luck

Cochese
April 16th, 2009, 11:14 AM
Mine hasn't yet in 200 miles. :rofl:

We'll see after the mods.

Sound Wave
April 17th, 2009, 01:04 AM
man, i thought i was in the clear. 1300 miles and had my first backfire at start up tonight. startled me a bit. hope it isn't the beginning of a trend.

capt_bugaloo
April 17th, 2009, 06:34 AM
Hmm. My 2008 let loose with a hellacious backfire yesterday when starting up. That is only the second or third time in over 2000 miles. It had only sat cold over night, and I was starting it the usual way - choke, no throttle.

sm0kediver
April 17th, 2009, 02:27 PM
My second backfire this week at around 850 miles.

Mo1981
April 21st, 2009, 02:38 PM
My '08 has about 4,500 miles on it and it has backfired twice in the past week. It's normally around 60-65 degrees in the morning here. It's getting to where I cringe before I hit the button.
Posted via Mobile Device

B2FiNiTY
April 21st, 2009, 04:39 PM
I just popped my backfire cherry today at 5XX miles. hahah it really surprised me.

paterick4o8
April 21st, 2009, 04:53 PM
it really surprised me.

yup. poppin the cherry tends to lead to that effect. it sure got me :confused40:

Rocketman
April 27th, 2009, 01:14 PM
i have a feeling it might have somthing to do with letting the bike idle for a few seconds before you shut it down...at least thats the way it is with my sled and stuff

Viper-Byte
April 27th, 2009, 01:22 PM
I usually let my bike idle for 10-15 seconds after a ride before shutting it down and the backfire is not a common occurance. So I don't think it is that.

Rocketman
April 27th, 2009, 01:24 PM
I usually let my bike idle for 10-15 seconds after a ride before shutting it down and the backfire is not a common occurance. So I don't think it is that.

Maybe why that's why its not a common occurrence ? left over fuel in the exhaust system maybe ? Backfiring can also occur in carbureted engines that are running lean where the air-fuel mixture doesnt have enough fuel and the timing too advanced.

Rocketman
April 27th, 2009, 01:29 PM
grabbed this off the net for you guys...

* Poor or unregulated engine timing is often a cause of intake backfires, but can also be responsible for exhaust backfires
* Improper wiring in the ignition can also lead to timing issues and backfires
* Low fuel pressure, clogged fuel filters, and weak fuel pumps could cause a severe lean air-to-fuel ratio during fuel injection
* Missing or damaged catalytic converter can result in backfires out the tailpipe

sports exhausts (both factory-fitted and aftermarket) are much more likely to backfire. In some circumstances the backfire is seen as an additional perk of the car. The TVR Cerbera is an example of a car factory-fitted with sports exhausts, leading to a large amount of backfires on engine braking.

paterick4o8
April 27th, 2009, 01:39 PM
i have a feeling it might have somthing to do with letting the bike idle for a few seconds before you shut it down...at least thats the way it is with my sled and stuff

I don't see how you can not let you bike idle a few seconds before shut down unless you shut it off while you're engine breaking coming to your stop.

I dont think this is the cause either b/c I always let my bike idle for a while before shutting off and havent had any backfire from that

Rocketman
April 27th, 2009, 01:48 PM
I don't see how you can not let you bike idle a few seconds before shut down unless you shut it off while you're engine breaking coming to your stop.

I dont think this is the cause either b/c I always let my bike idle for a while before shutting off and havent had any backfire from that

I could be wrong....I didnt say I knew, It was an educated guess :p

g21-30
April 27th, 2009, 02:35 PM
RocketMan...I love your "Rear" Brakes in your avatar. I remember seeing "both" front and rear brake pictures a few months ago. When mine wear out, I'm going to get some of those! :D

BlueRaven
May 2nd, 2009, 07:20 PM
does the backfire occur in both stock exhaust and aftermarket? hasn't happened yet but i don't think i can prepare myself to my first time. Knowing me i'll jump off the bike and let it go so i guess i'll only start it when i'm not on it.

Viper-Byte
May 2nd, 2009, 08:46 PM
Mine has done it with both stock and AreaP. She backfired today again... :D

I done NOTHING different to what I usually do after my ride yesterday, it was a warm day, 16°C or so. got home, stand down, got off bike, took gloves off, turned key off. No playing with the choke or throttle was done between rides, started today no choke, about 16°C again and BANG! :D

CodE-E
May 3rd, 2009, 12:24 AM
I prefer the whistling gas tank anomaly to the exploding engine conundrum


How does that happen? I've observed that a couple of times myself, and I was a bit concerned about that. I wasn't sure where the sound was coming from. I thought it might be the front suspension fork or something.

sm0kediver
May 3rd, 2009, 04:30 AM
It's some sort of tank venting/pressure equalizing thing. Both Ninjas I have owned were pretty vocal.

g21-30
May 3rd, 2009, 07:44 AM
It's just the gas tank relieving the pressure built up! Mine is usually very vocal; however, yesterday after a ride, it was just doing an occasional spiiizzz... Really got me to laughing about it. :D

CodE-E
May 3rd, 2009, 08:48 AM
Ahh, okay. Nothing to worry about then.

Mine does it when it's been standing for a couple of hours, and I move it off its stand into an upright position, so I guess as soon as the fuel in the tank is shifted around a bit.

Lurkable
May 7th, 2009, 11:32 AM
Ahahaha, finally happened to me today and it was shocking!! 6 months after I bought the bike and now I know what you guys mean when you say "loud."

I had it up on the rear stand about 20 minutes prior as I was cleaning the chain...dunno if this kind of movement could have anything to do with it. I always turn off the ignition as I am coasting into my driveway so the engine has already stopped running before I even come to a stop.

chess
May 22nd, 2009, 09:39 PM
I'm in the club!

All stock...750 miles.

H.I.D.
June 15th, 2009, 02:13 PM
If it is the gas tank that is relieving the built -up pressure that makes the
bike backfire, Has anyone tried opening the gas lid 1'st, and then close it
and then proceed to start the bike ?

Sound Wave
June 15th, 2009, 03:15 PM
hid, since it doesn't happen all the time, i would think it would be hard to tell if doing that helped or not. plus, i couldn't imagine having to open and close the gas tank every time you start the bike.

for me, i took the advice on this forum and i just let the bike run a bit at idle before turning off the engine. knock on wood, it hasn't happened again since.

g21-30
June 15th, 2009, 04:14 PM
If it is the gas tank that is relieving the built -up pressure that makes the
bike backfire, Has anyone tried opening the gas lid 1'st, and then close it
and then proceed to start the bike ?

Don't get the gas tank "whistle" mixed up with the backfire! The gas tank mention in this thread was "off topic" by some of us who have experienced both the "whistling" and the backfire. One does not cause the other! :D

laughrey
June 23rd, 2009, 10:11 PM
It is really really loud. It has happened to me at early morning start up and (on another day) when I was leaving work. I'll try letting it idle for a few seconds after I stop. Good advise.

g21-30
June 24th, 2009, 05:06 AM
It hasn't happened to me in a while. I haven't changed anything, i.e. idle before turning off the engine, etc. When I'm ready to park it, I turn off the ignition. When I start it up, I do it with the expectation that is IS going to backfire. That way I'm NOT surprised, if it does. :eek:

M-Oorb
June 24th, 2009, 05:46 AM
Happened to me for the first time this morning after 2300 miles...scared the poop out of me. I'm sure a bunch of people in new brunswick ducked a little
Posted via Mobile Device

Banzai
June 24th, 2009, 08:32 AM
Had the bike for over 4K miles, never a backfire. Read this thread yesterday and sure enough, on start up this morning, POP, and I about crapped my pants. Inside my garage, that was loud as hell, and I think I took out one of my cat's 9 lives.

g21-30
June 24th, 2009, 10:22 AM
Had the bike for over 4K miles, never a backfire. Read this thread yesterday and sure enough, on start up this morning, POP, and I about crapped my pants. Inside my garage, that was loud as hell, and I think I took out one of my cat's 9 lives.

That settles it. If you think about it, it WILL HAPPEN! Kind of like "target fixation!"

Sound Wave
June 24th, 2009, 10:41 AM
When I start it up, I do it with the expectation that is IS going to backfire. That way I'm NOT surprised, if it does. :eek:

me too. before, i used to turn on the engine and then start gearing up. now i put my ear plugs in FIRST, then start the engine and finish gearing up.

ajaygraci
June 24th, 2009, 11:35 AM
mine shot fire out the back after winter storage... i didnt really hear it but my ma said she saw fire come out n she jumped.. i was just liem.. meh maybe my full system?

Mike1357
June 24th, 2009, 07:57 PM
That settles it. If you think about it, it WILL HAPPEN! Kind of like "target fixation!"

Aw, crap. I should have never read this!!
lol
At least I won't freak out and think somethings wrong if/when it does happen.

Monica
July 10th, 2009, 02:51 PM
This is so funny. Mine just did it for the 2nd time. The first time I thought something broke or fell in my garage. My husband's bike was running next to mine when I started it up & kind of deadened the sound, I still freaked out, but we didn't know for sure where it came from! They should put a warning label on these things, someone's gonna get a heart attack! I'm so happy to see everyone else has the same issue, now I'll be better prepared. I have about 250 miles on the bike so far.

g21-30
July 10th, 2009, 03:04 PM
This is so funny. Mine just did it for the 2nd time. The first time I thought something broke or fell in my garage. My husband's bike was running next to mine when I started it up & kind of deadened the sound, I still freaked out, but we didn't know for sure where it came from! They should put a warning label on these things, someone's gonna get a heart attack! I'm so happy to see everyone else has the same issue, now I'll be better prepared. I have about 250 miles on the bike so far.

Monica,

Congrats, you passed the Ninja 250 initiation ritual! But don't worry, this event keeps on giving and giving. I bet it happens again when you least expect it! :)

noche_caliente
July 13th, 2009, 05:18 PM
I had my first backfire this morning - not much of one, but there none the less - didn't give me a heart attack at least...

g21-30
July 14th, 2009, 03:32 AM
Kim,

Welcome to the club!

lockie
July 14th, 2009, 04:56 PM
Two little backfires in two days. Both times I had an audience. Does the bike have a performance complex and likes acting up in public?

g21-30
July 14th, 2009, 05:09 PM
Two little backfires in two days. Both times I had an audience. Does the bike have a performance complex and likes acting up in public?

Likes to sing (gas tank) and break wind (backfire)! Definitely loves an audience. Welcome to the club. One day the stars will line up just right (when you least expect it) and you'll get a real boomer.:loco:

backinthesaddleagain
July 24th, 2009, 08:37 PM
Backfired tonight then wouldn't start (with or 2/o choke) for a few minutes. Then even with choke it idled around 2k rpm for a couple minutes before finally climbing. Rode a few miles, pulled over and saw idle was back to 1500 rpm (no choke). Battery took a hit after trying about 6 times to start bike. On the tender tonight. See what tomorrow brings.

g21-30
July 25th, 2009, 12:14 PM
When my bike is parked, it's always on the battery tender. The tender only charges if the battery needs it. :)

backinthesaddleagain
July 25th, 2009, 05:52 PM
First time on tender since May. No battery problems until last night. I think part of it was mis-start turned headlight on. I should have turned key off and on before trying to start bike again and only starter would be drawing from battery rqther than starter and headligjt.
Posted via Mobile Device

i916it
July 28th, 2009, 02:32 AM
How to force backfire to occur?

Dipmode
July 28th, 2009, 01:16 PM
yea its so funny when it happens where i live in cause i live in the middle of the city in a not so good part of town. but i think it happens when the carb is flooded or somthing like that all i know is that when it happens its really loud

bostonmichelle
August 7th, 2009, 09:25 PM
Mine started backfiring around 2500 (I think?) miles, and it's done it about 5-7 times since (I'm at 4200 miles now). I guess misery loves company because I'm very happy to hear that it's not just my bike. I understand that it can be pretty harmful. Makes me wonder if there's going to be a recall or a class action suit or something if all our bikes crap out early from it!!

Has anyone actually found a mechanic who diagnosed and fixed it? Anyone have their 7500 mile service yet??

TheDuck
August 7th, 2009, 09:52 PM
How to force backfire to occur?

Get the bike warmed up, give it a little rev to like 5-6k, and kill it with the switch. Just before you hear the engine stop turning flip it back on. If you get the timing right this will result in a nice BANG and a 18" flame out of your exhaust pipe. The better the timing, the louder the bang.

Pretty much any carbureted vehicle will do this as fuel delivery doesn't rely on electronics and works only by air flow.

Mine started backfiring around 2500 (I think?) miles, and it's done it about 5-7 times since (I'm at 4200 miles now). I guess misery loves company because I'm very happy to hear that it's not just my bike. I understand that it can be pretty harmful. Makes me wonder if there's going to be a recall or a class action suit or something if all our bikes crap out early from it!!

Has anyone actually found a mechanic who diagnosed and fixed it? Anyone have their 7500 mile service yet??

There is nothing wrong with your bike:

This is not a "backfire" like many people call it, but rather an *after*fire as it is unburnt fuel in the exhaust pipe being ignited and blown OUT and AFTER the engine. With a stock exhaust the catalytics and all the baffling chambers prevent the anything too exciting from happening.

Real BACKfiring is harmful as it blows BACKWARDS through the intake, this is typical when ignition timing or valve timing is VERY wrong. It can also happen if the engine is overheating and/or detonating and ignites the moment the air/fuel charge enters the engine while the intake valves are still open. Seals can blow out, small parts in carbs can be broken, holes can be blown in pistons, dangeous fires can be started, and airboxes can COMPLETELY explode (more common if you are using any form of nitrous.)

I've seen a cone filter on a Civic blow up like a basketball after a nitrous backfire, haha.

tc3jg
August 8th, 2009, 08:34 AM
These backfire stories are funny..

Add me to the club...after work I went to start up the ol ninja and BANG I MEAN LIKE big bang not a little sputter but like someone else said a cannon. I didnt think it came from my bike as I have had my after market full exhaust installed for at least 400 miles before the backfire. I was looking around like wtf who crashed ..who dropped something. It scared the poo out of me.

So to confirm that it was my bike about 4 days later was in the same spot doing the same thing and it had another pop but wasnt as loud as the first one.

all I do is pull in the my motorcycle spot turn the wheel to the wheel lock position turn the key to the off position and into the lock position. and off it goes get off the bike and walk away. I dont choke the bike because here it is around 70-90 degrees( summer in Illinois)...

bostonmichelle
August 8th, 2009, 09:24 AM
I feel much better now. Don't know who you are or your qualifications, but you sound knowledgeable enough!

I'll officially begin to enjoy it when it happens - I'll look around to see if anyone around me ducked for cover, and I'll laugh my head off. :cool:

noche_caliente
August 9th, 2009, 06:58 AM
Welcome to the forum Michelle! Be sure to post up an intro in the new members section!

TheDuck
August 9th, 2009, 11:01 AM
I feel much better now. Don't know who you are or your qualifications, but you sound knowledgeable enough!

I'll officially begin to enjoy it when it happens - I'll look around to see if anyone around me ducked for cover, and I'll laugh my head off. :cool:

Haha, I just figured out how to get my lawnmower to do it, too!

Its not as impressive (the exhaust is tiny, it can't fill up with much air/fuel mixture) but it still got a nice pop and a little flame came out! :)

shadow
September 14th, 2009, 07:52 PM
had mine before my second ride on the bike, but knew exactly what it was. happened with no helmet or ear protection, in an open indoors garage with the tail facing the inner wall. Sadly I can't say i was devirginized as I used to go shooting frequently, and didn't always wear protection. Guess it was more of an "Oh, well good morning to you too sweetie!" :kiss:

bostonmichelle
September 14th, 2009, 09:45 PM
As suggested in this or some other forum, I've been letting it idle for a minute before turning it off, and I haven't had a boom since. I'm not saying that this is the cure, but it's working for me so far.



***EDIT 9/15/09*** I JINXED MYSELF! Just this morning, the morning after I wrote the above note, it "backfired" again! Forget about idling it before turning it off. It doesn't work!! Sigh.

g21-30
September 15th, 2009, 03:40 AM
Welcome to the "Club" Joe and Michelle! Mine hasn't done it, since I retrofitted the '88-94 CDI, but it probably will, now that I mentioned it!

My gas tank still whistles and my grand kids love that when they hear it.

kkim
September 15th, 2009, 10:27 AM
As suggested in this or some other forum, I've been letting it idle for a minute before turning it off, and I haven't had a boom since. I'm not saying that this is the cure, but it's working for me so far.



***EDIT 9/15/09*** I JINXED MYSELF! Just this morning, the morning after I wrote the above note, it "backfired" again! Forget about idling it before turning it off. It doesn't work!! Sigh.

lol :D

bostonmichelle
September 15th, 2009, 10:31 AM
I just got saddle bags, tank bag, and tail bag for the Ninja as we're planning a big Christmas/New Years trip to San Fran from LA. I got the saddle bags on Saturday & promptly went out to try them on. I hadn't ridden the bike since Friday, but for some reason, while I was putting on the bags, my little girl started making little sighs! It was so funny that I started talking to her about the trip! I think she's excited!

Note to self: do not admit talking to motorcycle on public forums!

g21-30
September 15th, 2009, 11:07 AM
You had me going there for a minute, when you said you were talking to your little girl! It's time for me to leave work...went right over my head.

noche_caliente
September 15th, 2009, 03:37 PM
I just got saddle bags, tank bag, and tail bag for the Ninja as we're planning a big Christmas/New Years trip to San Fran from LA. I got the saddle bags on Saturday & promptly went out to try them on. I hadn't ridden the bike since Friday, but for some reason, while I was putting on the bags, my little girl started making little sighs! It was so funny that I started talking to her about the trip! I think she's excited!

Note to self: do not admit talking to motorcycle on public forums!

Don't worry - I talk to mine too - she gets very excited when we get ready to go somewhere and very upset when she sees me getting in the cage... my son even asks "mommy, why your motorcycle crying? she want you to ride her?"

bostonmichelle
September 15th, 2009, 03:41 PM
Don't worry - I talk to mine too - she gets very excited when we get ready to go somewhere and very upset when she sees me getting in the cage... my son even asks "mommy, why your motorcycle crying? she want you to ride her?"



That's so cute!! And, thank you for the support!

jupiter1827
September 25th, 2009, 01:11 AM
I have about 7k miles on my ninja now, but I have had this problem pretty much since I got her almost a year ago. I ride it to work everyday, and though it is embarrassing when I start it up and it does this, I never really thought too much about it... until today. There was a couple walking right behind me when I reached to start it up. Luckily I thought twice and waited until they walked by. After I started her up, bang!!! The lady turned around, and the look on her face... I think she thought someone fired a gun - I had to reassure her that it was just my motorcycle. Wow, I felt so bad.

I live in Hawaii, so there's no crazy change in temperatures, but it does rain a lot. Pretty much every day it rained/misted, I could bet that I would get that loud backfire sound, so I thought maybe water vapor got inside, and when the engine started up, the vapor expanded, and pow! However, I don't remember it raining today. :( I did read on a Harley forum that it could have something to do with the fuel mixture etc. I guess I'll take it to a shop and see what they say.

Sorry for the novel, but I thought it was kind of a funny story - after the lady recovered that is.

kkim
September 25th, 2009, 01:20 AM
It's normal for these bikes. Don't worry about it.

Welcome to ninjette.
:)

g21-30
September 25th, 2009, 03:35 AM
Jen,

It's not unique to rainy/misty areas. It's just that the bike likes to express its opinion via backfire and/or singing via the gas tank! :)

g21-30
September 29th, 2009, 03:00 PM
Two weeks to the day! My bike had a healthy backfire at startup this afternoon. Lady a few houses down was working in her flower garden. It gave her a pretty good startle, So much for the thought that the CDI retrofit fixed it! I knew I shouldn't have mentioned it. :confused:

Samer
October 8th, 2009, 04:36 PM
My Ninja is completely stock. I have about 200 miles on it and last week was the first and only time the BANG occurred for me so far. This was of the shotgun variety and it scared the S*HIT out of me. Mainly because I completely didn't expect it. As someone already commented, I also prefer the whistling tank sound since that one is kinda cute.

killerkay3
October 8th, 2009, 05:07 PM
My Ninja is completely stock. I have about 200 miles on it and last week was the first and only time the BANG occurred for me so far. This was of the shotgun variety and it scared the S*HIT out of me. Mainly because I completely didn't expect it. As someone already commented, I also prefer the whistling tank sound since that one is kinda cute.



haha

g21-30
October 8th, 2009, 05:22 PM
My Ninja is completely stock. I have about 200 miles on it and last week was the first and only time the BANG occurred for me so far. This was of the shotgun variety and it scared the S*HIT out of me. Mainly because I completely didn't expect it. As someone already commented, I also prefer the whistling tank sound since that one is kinda cute.

You have now been initiated! Welcome to the club of "Backfires and Whistles!"

overload
October 9th, 2009, 01:18 PM
Does this only occur in the carburated models ? Do the FI models also backfire ?:confused::confused:

Cedilla
October 11th, 2009, 11:06 PM
Mine has only backfired once when starting it up, I think it was because it had been sitting for a week. Also I had trying to get it started for about 30sec before it happened, then BOOM!!!!, then it started but, was hard to keep idling for a couple of min. Also my gas tank whines almost constantly, but it usually does it as somebody is walking up to it, I have to explain it to someone almost daily, but I don't mind.:)

g21-30
October 12th, 2009, 07:16 AM
Does this only occur in the carburated models ? Do the FI models also backfire ?:confused::confused:

Sorry, I don't know. If you have it happen, please post and let us know.

athimmel
October 15th, 2009, 08:23 AM
Well, mine just lulled me into a sense of security after not doing it for a while. Then, this morning...KABOOM!! Just about destroyed two sets of eardrums. (Wasn't pulled out of the garage far enough!) Mine is stock, and has about 1200 miles. Third time for a major after/backfire. At first, I thought it was because I used mid-grade gas, so I went back to regular. A month or two later...the return of the boom. This morning was the first day riding after 2 days of rain. I always end up idling a bit before turning off the bike, because I thought it might burn off last bits of fuel. Nope.

I think the neighbors thought there was a murder on the streets. Sound like that in a quiet subdivision causes a lot of attention.

RedCromwell
August 12th, 2010, 05:26 PM
My stock 2010 backfired the day after I got the 600 mile service done. Freaked me out and made wonder wth the dealership did.

Didn't do it again for awhile so I figured it was just a fluke... maybe moisture in the exhaust... then it happened again.

So, far it's probably happened about three times in total each time at first startup in the morning with no rhyme or reason.

After hearing others with the same experience I'm not concerned about it.

Hitman
August 16th, 2010, 01:18 PM
Consider me in the "club". Mine did its bang at about 8AM and about 70 degrees as I started it. It was at about 250miles.

I did rev the throttle before I turned it off the night before. Damn that is loud. Luckily I had a heavy backpack on so my movement from the shock was minimal after I heard it. :)

bdavison
August 16th, 2010, 01:27 PM
My neighbors dog has a habit of bounding up to the fence and woofing a low "Im gonna getcha" bark. Im used to it and just ignore him...

So anyway, the other day I pull my bike out, and hop on it, and here comes that dog...woof wooooooof woooof......






KAPOW!!!!!!!!!!!!!!!!!!!!!!!!!



Arf Arf Arf Arf Arf.


I almost dropped my bike I was laughing so hard.

Jibs
August 18th, 2010, 11:57 AM
a normal occurence or not, does anyone have a way of preventing it from happening. My 08 will do it EVERY first startup of the day :confused:

kkim
August 18th, 2010, 12:00 PM
have you tried not turning the throttle at start up?

plus, do you play with the throttle while the bike is off and parked between startings?

Jibs
August 18th, 2010, 12:05 PM
hey kkmin,
No i dont play with the throttle on startup, and the throttle is not used when the bike is off.
With or without choke on startup is still happens. I aslo tried letting the bike idle before i shut it down.

kkim
August 18th, 2010, 12:08 PM
has it always done this or is this something recent? I notice you have an 08... how many miles on it?

Jibs
August 18th, 2010, 12:11 PM
my mistake its a 09, happened once between 0-700miles, but now at 800 miles its been happening during every first startup of the day after not riding it for at least 1-3 days. The only thing diff that i did was change the oil, but i dont think that could be causing it. Bike is stock also.

kkim
August 18th, 2010, 12:21 PM
I agree... the oil change should not affect what is happening w/ the backfiring and popping on every cold start of the day does seem a bit excessive.

Jibs
August 18th, 2010, 01:01 PM
That what I was thinking, any suggestions? Is there anything done on the first inspection that could cause/fix this?

kkim
August 18th, 2010, 01:04 PM
Sorry, I can't think of any. The starting backfire is mostly an isolated/infrequent incident and even at that, people have not been able to find the real cause. That yours is happening on a regular basis has me stumped. :confused:

Cuongism
August 18th, 2010, 01:16 PM
Interesting, I've had my 250 for about 1500 miles, a little over 2 months (currently at 7300 miles). For my first 1300 miles, it's never done this. However, after I changed my oil and filter it backfired twice the past two weeks. The other change I made was I stopped using the killswitch to shut off my bike. Before, I would kill the engine and then roll to park. Now I park with the engine running in neutral and then shut off the bike with the key after I parked (so it'll idle for a bit while I park).

fuzion
October 22nd, 2010, 05:06 AM
I have a 2009 Ninja 250. The backfire started happening around 2500 miles and still happens at roughly 3500 miles. I've had all the regular owner's maintenance performed as per the manual. I have stock exhaust, air filter, etc.

Since I'm in Canada the weather here is already quite cold at 2 degrees Celsius in the morning (35.6 degrees Fahrenheit).

What really baffles me is that on Tuesday, Wednesday, Thursday, and Friday it starts up just fine with no backfire. Almost every Monday after it has been sitting for 2 days I am almost guaranteed to get a backfire.

I have a short ride to work so I found that taking the highway instead of the scenic route seems to slightly reduce the occurrence of backfires but it does not get rid of it. I suspect that driving at higher speeds or for a longer time keeps the battery better charged. I also let it idle for 10+ seconds before shutting it off. I used to shut it off with the key but had too many backfires. For some reason, using the kill switch seems to result in slightly less backfires (but they're still there). I always use the choke to start it cold (otherwise it wouldn't start with this weather). Before it got cold I had backfires with and without the choke. Also I don't play with the throttle at all, each start is identical. The only difference is the 2+ days of not riding it.

Does anyone have any idea why leaving it sit for 2+ days seems to drastically increase the odds of getting a backfire on a cold start?

I don't understand why leaving it sit in a garage for 48+ hours would cause a backfire whereas leaving it sit in a garage for 10 hours would not cause a back fire. i.e. could the engine really get any colder after sitting for 10 hours?

Also, I've confirmed that flames come out the exhaust when it occurs. I always stare at the exhaust when I turn it on in the morning and if I start it before sunrise I'm sure to see a 12" flame shoot out the exhaust. It's a lot of fun and I could care less if I lived in the country, but since I live in the city and am surrounding by pain in the ass neighbors, I would prefer not to have the backfire.

Also, my garage is not heated. I wonder if I would get this if I had a heated garage.

Based on what I read, it seems like unburnt fuel is getting into the exhaust and is later being ignited when in the exhaust. Could there be something like condensation building up in the exhaust over 2+ days that could be causing this?

I've thought about rejetting or shimming but I don't see how that could fix the problem.

Could it have something to do with the battery? Could the battery be weaker after sitting for 48+ hours in cold air that it is causing a backfire? Would getting new spark plugs help?

scotty
October 28th, 2010, 08:27 AM
I would like to make a note..

My bike did this also, but after I installed a full exhaust and removed the Kleen air system, it has not done it. I think it may have something to do with the Kleen air system on the bike. Im not 100% sure on this, but like I said, it hasnt happen to me since then. Can anyone who has taken off there Kleen air system agree to this?

g21-30
October 28th, 2010, 09:02 AM
Can anyone who has taken off there Kleen air system agree to this?

Nope! Still backfires, just louder :eek: with the full exhaust!

lux
October 28th, 2010, 09:59 AM
First one this past weekend. Had my earplugs and helmet on already. hehe

fuzion
October 28th, 2010, 04:29 PM
g21-30, did you also do the kleen air mod?
scotty, how long has it been since you did the kleen air mod?

I haven't had any backfires for a few weeks now as long as I take it out at least once for a good ride during the weekend.

Can anyone explain how the kleen air mod would prevent unburnt fuel from entering the exhaust (and causing the backfire)?

g21-30
October 28th, 2010, 04:56 PM
g21-30, did you also do the kleen air mod?


Yes!

scotty
October 28th, 2010, 07:21 PM
It has been a few months now. I havent had any back fire since. So my guess has been ruled wrong lol

fuzion
November 4th, 2010, 02:23 PM
Thinking about winter storage again I just checked the user's manual for a refresher.

"Tie plastic bags over the mufflers to prevent moisture from entering."

Moisture in the muffler couldn't cause this could it? Maybe I should start tying plastic bags over the muffler during the weekend :) or maybe I should start spraying water in the muffler to see if that is causing the problem.

g21-30
November 4th, 2010, 04:27 PM
^^^Moisture (water) is a byproduct of combustion. It's not going to cause backfire or prevent same.

fuzion
November 9th, 2010, 12:42 PM
I'm not a mechanic so I don't know how unreasonable these suggestions are.

Could it be possible that condensation is getting in the combustion chamber when the bike is sitting for a long time in cold and humid weather (or because of the way the bike is shut off)? i.e. at first cycle there's no ignition so unburnt fuel gets pushed to the exhaust, but the next few cycles there's ignition and then it also ignites the fuel in the exhaust (kaboom). Could this happen if there's water in the combustion chamber before ignition occurs?

My bike was just parked for over a week so I was surprised when it didn't backfire when I started it up yesterday. The first thing that I thought of is that it's so cold now that there's not much humidity in the air.

It's hard to understand how it can occur due to being too lean or too rich because it happens with and without the choke. If it was one way or the other then couldn't you prevent it by using the choke to control the air to fuel mixture during startup?

Maybe next year I'll keep a log of the temperature, humidity, and time parked to see if there is a relationship to the backfire. i.e. "if parked over X hours with Y% humidity then it's guaranteed to backfire", but even if that's the case, not sure how it would help... :rolleyes:

ungluck
February 3rd, 2011, 12:40 AM
i have a 2010 250r and it has 836 mile son it..and the tank sings and it backfires atleast once a week at start up.

now..i know for a fact the bike runs rich..probably too rich, and that will def make this happen. i have a spot in our garage, bikes goes there idles for a sec then shuts down and isn't touched till next day. so i would assume, likely cause is due ot it being so rich at start up as well as idle...my ninja has some struggling(riicch) issues at idle.

now the tank singing, is there a vent for evap on/in/for the tank? it's mostly due to the build up of evaprated fuel and it seems to me there is no way for it to escape or be used/recycled like in modern vehicles.

just my insight..but being that i know my bike is rich..i think i'm gonna pull my snorkel :]

fuzion
February 3rd, 2011, 05:13 AM
I think you're right.

I think last year my bike idled around 2300-2500 (a far stretch from the spec of 1300+-50). So the first thing I'm going to try this year is getting the idle back around 1300 using the idle adjust knob. If for some reason that knob doesn't work then I'll take it in to a dealer to get looked at.

Having it run rich seemed to help some days in the cold Canadian climate but I don't want it to backfire anymore. If anything, I'll just have to wait longer for it to warm up in the morning.

My guess is that if it is running rich then it is sucking too much gas, even at idle. So when it gets shut off some of the excess gas is left in the exhaust, unburnt. Then when it is fired up for the first time there is an instant backfire (since the excess gas is already ready and waiting in the exhaust). Either that or maybe the gas is evaporating somehow into the exhaust when it is off, but you would think that shouldn't be possible. The backfire for me happens the instant the ignition button is pressed. I think this means that the gas was already there in the exhaust prior to hitting ignition. I'm also going to try inspecting the exhaust a few times this year, i.e. see if I can smell gas in the exhaust prior to hitting the ignition.

If there is gas in the exhaust prior to ignition and it can't be prevented, then I wonder if there would be a way of clearing out the gas without the bang.

I checked the weather history from previous backfires and I couldn't really make a connection. The air pressure seemed higher during weekends where it backfired but there were also high air pressure periods where it didn't backfire.

I'm wondering if it's a 'luck of the draw' on how it shuts down and how much gas it is drawing at the time. Maybe we could test it by revving the engine prior to shutdown and see if there is a guaranteed backfire on the next startup.

Also this year I'm planning to keep the bike hooked up to a trickle charger when it is parked overnight/weekends in case I'm not riding it enough to keep the battery fully charged.

As for the tank singing, I'm not worried about that. My neighbors won't kill me over a singing tank (compared to a shotgun blast at 6:00AM). I saw somewhere online a mod to fix it but it required custom drilling to the gas cap so I didn't bother.

I'm starting to wonder if I should trade in my ninja for a new CBR 250 since it's fuel injected. It likely won't have backfires or a singing tank.

fuzion
February 3rd, 2011, 05:21 AM
I just looked up the snorkel removal:
http://www.kawiforums.com/ninja-250r/106228-diy-removing-snorkel.html

It seems like a quick and easy way to fix being too rich.

I wonder though, since it's called a snorkel, if too much water would get in with the snorkel removed (I like to ride in the rain).

I should try that if the idle adjust knob doesn't work (and maybe skip the rain).

ungluck
February 3rd, 2011, 12:26 PM
i did my idle adjustment after the bike was hot and had been running, i even fiddled with it at long lights, to fine tune it cos it would change. been perfect ever since.

i do know that my bike, has to be warmed up or it's pissed off driving cold cos it runs so rich, tempted to pull my a/f gauge outta my car to see where exactly..but...that's alot of work lol.

fuzion
February 3rd, 2011, 05:03 PM
What was your idle when your had backfires? How do you know if it is running rich?

I thought that an unstable idle had more to do with carb syncing than a/f mixture.

dubojr1
July 13th, 2011, 08:21 AM
Ok guys I may have a solution. Mine has backfired since it was new. It seemed to be more frequent after starting all the performance mods and I have scared the bejesus out of a few people walking to their cars in the covered parking garage I have at work. I thought originally nothing of it and figured the backfire would return but I can say now that I went from at least a couple backfires a week to zero after doing the fuel lid mod. Not only did I get rid of that annoying whine but the bike hasn't backfired since.

Just wanted to put it out there as a possible solution. Anyone having the backfire issue done the fuel lid mod?

shiroganeshinobi
July 13th, 2011, 08:47 AM
Are you guys turning off your bike via ignition or how the MSF teaches with the kill switch?

If it's the latter, try turning your bike off with key for awhile.

dubojr1
July 13th, 2011, 08:49 AM
Are you guys turning off your bike via ignition or how the MSF teaches with the kill switch?

If it's the latter, try turning your bike off with key for awhile.

I always turn my bikes off with key just for reference.

csviegas
July 13th, 2011, 09:11 AM
I always turn my bikes off with key just for reference.

I used to turn off with the key too, but someone on the forum had mentioned that the radiator fan doesn't kick on if its needs to once the bike is off. Since then I have turned off with the kill switch and have noticed that the radiator fan does indeed kick on for a couple of seconds sometimes on a very hot day.

dubojr1
July 13th, 2011, 09:21 AM
I used to turn off with the key too, but someone on the forum had mentioned that the radiator fan doesn't kick on if its needs to once the bike is off. Since then I have turned off with the kill switch and have noticed that the radiator fan does indeed kick on for a couple of seconds sometimes on a very hot day.

Sorry... Someone was mistaken. The fan in fact will run if needed after turning the bike off with the key.

csviegas
July 13th, 2011, 09:29 AM
Sorry... Someone was mistaken. The fan in fact will run if needed after turning the bike off with the key.

Ok thanks. Good to know.

shiroganeshinobi
July 13th, 2011, 09:30 AM
I used to turn off with the key too, but someone on the forum had mentioned that the radiator fan doesn't kick on if its needs to once the bike is off. Since then I have turned off with the kill switch and have noticed that the radiator fan does indeed kick on for a couple of seconds sometimes on a very hot day.

Shouldnt be the case, the fan will run either way. Your car does this after you turn off the car and so should your bike. I'm not saying you shouldnt use the kill switch, but it's possible cause for a backfire. Just ruling out the simple reasons. I'm dont know what mods you have, but the mixture is probably off. In what way, that's the headache part everyone is banging their head on.

dubojr1
July 13th, 2011, 09:34 AM
Shouldnt be the case, the fan will run either way. Your car does this after you turn off the car and so should your bike. I'm not saying you shouldnt use the kill switch, but it's possible cause for a backfire. Just ruling out the simple reasons. I'm dont know what mods you have, but the mixture is probably off. In what way, that's the headache part everyone is banging their head on.

The backfire seems to happen over a long range of bikes with different mods so that makes me think it is something stock, factory set, or original to design. The fuel lid would fit that. My stock bikes had this issue and my modified bikes had this issue until the fuel lid mod.

greatwhiteninja
July 13th, 2011, 09:38 AM
mines done it twice.. once while riding on a deaceleration from around 10k rpms.. that was a loud POP! my buddy riding with me who has a loud harley even herd it and was like was that you!!..loL! other time was about a week ago when i first fired it up, let out a nice POP!

dubojr1
July 13th, 2011, 09:40 AM
mines done it twice.. once while riding on a deaceleration from around 10k rpms.. that was a loud POP! my buddy riding with me who has a loud harley even herd it and was like was that you!!..loL! other time was about a week ago when i first fired it up, let out a nice POP!

Yeah the decel "pop" is normal to a certain point. Have you removed the clean air system? The start-up backfire is the one we just can't seem to pinpoint.

Sound Wave
July 13th, 2011, 03:31 PM
Just wanted to put it out there as a possible solution. Anyone having the backfire issue done the fuel lid mod?

it still backfired on me even after the mod.

fuzion
July 14th, 2011, 04:35 AM
Unfortunately I lost my bike due to someone having ran it over with their SUV at my work parking lot. Fortunately the guy stuck around so I had no deductible to pay on my insurance claim. I'm hoping to upgrade to a 600cc bike with fuel injection since this backfire issue was so annoying for me.

The fuel lid mod should have nothing to do with the backfire.

I rode my Ninja until almost the end of June in 2011 without a single backfire. I just kept the idle as close to the 1,350 RPM spec as possible. I found that I had to adjust the idle knob quite a bit since the weather fluctuated so much from week to week.

As a result, the bike had poor response and stalled a few times at intersections with such a low idle RPM when the whether was too cold (but then again, maybe I didn't let it warm up long enough).

I think the cause of this startup backfire is that the engine is sucking too much gas when it is shut off. As a result there is some leftover gas that is unburnt in the exhaust. So when the bike is started the next time it backfires. I think the best way to try and prevent this is to ensure a low RPM idle prior to shutoff.

dubojr1
July 14th, 2011, 04:45 AM
it still backfired on me even after the mod.

Does yours still whine a little after the mod?

I think the cause of this startup backfire is that the engine is sucking too much gas when it is shut off. As a result there is some leftover gas that is unburnt in the exhaust. So when the bike is started the next time it backfires. I think the best way to try and prevent this is to ensure a low RPM idle prior to shutoff.

I don't think I agree with this thinking. Some claim to only have the issue after 2 days of the bike sitting. Wouldn't any fuel in the exhaust evaporate in 2 days...

Don't get me wrong here guys. I'm not saying a circular shaped piece of aluminum (fuel lid) is causing our bikes to backfire, I'm saying it could be a venting issue of some sort because of the fuel lid. :idunno:

greatwhiteninja
July 14th, 2011, 05:48 AM
Yeah the decel "pop" is normal to a certain point. Have you removed the clean air system? The start-up backfire is the one we just can't seem to pinpoint.

yeah the clean air system is removed, actually it did the backfire on decel within 10mins of my first ride with the airbox removed and pod filters installed.. havent herd it since though, that was around 700 miles.. got around 1100 now. the start up backfire i assumed did it cause ever since re jetting i dont need to choke it when i fire it up, cold or warm.. and it was a cold start and i didnt even give it gas, just pushed the button, fired up for a split second and it let the pop out and cut off. refired and all was fine.

Lou
October 3rd, 2011, 05:07 PM
Had a HUGE embarasing backfire today at walmart... scared the crap outa myslef and everyone around. I knew it was me, but i looked around confused trying to find the source :D im not sure they realized it was me because the sound bounced off of everywhere. Parking lot patrol got spooked pretty good LOL

choneofakind
October 3rd, 2011, 05:46 PM
I knew it was me, but i looked around confused trying to find the source :D im not sure they realized it was me because the sound bounced off of everywhere.

fartin' in the elevator much? :D :D :rofl:

Lou
October 3rd, 2011, 07:09 PM
MEEEE?...No! :lie: Wouldnt hurt to wear one of these though :painkiller: :D

Kurgan
October 3rd, 2011, 07:28 PM
The only time mine has ever backfired was right after a wash if I got too much water down the pipe.

Sounded louder than a 10gauge shotgun going off.

Mr.E
October 3rd, 2011, 10:55 PM
Oh wow. So I had no clue the bikes backfired until I read this thread. Today when I went to start my bike, I heard a loud pop noise. My neighbors were just pulling into the drive way and I thought it was them. I gave them an evil glare. I thought they were playing with those loud toy cap guns lol. Well. I feel dumb now.

Mountain Dew
October 4th, 2011, 12:09 AM
Mine first happened a few hundred miles ago (6500ish) early in the morning, about 645. The next one happened two days later at the same time. Both scared the crap outta me.

jdoucet93
January 4th, 2012, 10:02 PM
First time it happened to me was about 2 weeks after installing my DanMoto slip on. Of course it was dead silent in my nice little quiet neighborhood. Oh yeah, and it was 3:30 in the morning. ha

It's happened quite a few times since then. I notice it happens mostly when it's pretty chilly outside; Near or below 40*f and when the humidity is above around 60%. They are always accompanied by a nice loud gunshot-like sound and about an 8inch flame out the exhaust pipe. I've gotten to the point where I brace myself and stare at the exhaust tip during the first start up every day.

RaZeDaHeLL
January 30th, 2012, 08:56 AM
My bike backfired on startup a few times, usually when it sits for over a week. Sounded like a shotgun. Now I cover my ears on startup just in case.

I read somewhere on another forum that using the ignition cutoff switch might have something to do with it. I'm going to try cutting off the engine with the key instead and see if that helps.

Brooklyn
January 30th, 2012, 11:14 AM
If it helps anyone: the only time my bike ever backfired upon startup is after the throttle was opened in neutral and then it was parked for a while. To avoid this, I just make sure the throttle stays closed unless the bike is in gear.

gadgetguy1288
January 31st, 2012, 03:02 AM
Mines done it a few times now as well. The first Time it happened I almost had a freaking heart attack, I carry a gun on me whenever I legally can(Im not opening that can of worms in this thread) and I thought my pistol had "misfired" and I started checking myself rather frantically for new holes. lol

g21-30
January 31st, 2012, 05:10 AM
I'm going to try cutting off the engine with the key instead and see if that helps.

Nope, won't help. That's how I always turn off my bike. Eventually, every 250 will do it, that's just it's nature. And it will do it when you least expect it. I've grown to expect it, but it still surprises me, just not as bad as the first time.

I've tried to make it happen, by twisting the throttle before shutting down or not twisting. It's sort of like the gas tank whistle, the bike is just trying to communicate with you. When it's lonely and wants to go for a ride, the tank will whistle when you come around it! :D When it backfires, it's just excited because it knows that it's going for a ride. :thumbup:

RaZeDaHeLL
February 3rd, 2012, 07:44 AM
I took my bike in for the 600 mile service and they said everything checked out good except the exhaust. Not sure exactly what the problem was but hopefully whatever they did will fix the backfire issue.

Oh and they said I had a couple screws missing! :eek:

NDspd
February 3rd, 2012, 07:52 AM
I took my bike in for the 600 mile service and they said everything checked out good except the exhaust. Not sure exactly what the problem was but hopefully whatever they did will fix the backfire issue.

Oh and they said I had a couple screws missing! :eek:

If you could, can you ask what they fixed?

Mr.E
February 3rd, 2012, 08:02 AM
Oh and they said I had a couple screws missing! :eek:

It's because you play with snakes. .... Oh wait, they meant the bike had a couple screws missing... oh.... nvm then... Uhmmmm. :D Just kidding :p

RaZeDaHeLL
February 3rd, 2012, 08:05 AM
If you could, can you ask what they fixed?

Yes I can call and find out...

It's because you play with snakes. .... Oh wait, they meant the bike had a couple screws missing... oh.... nvm then... Uhmmmm. :D Just kidding :p

LOL yea I definitely have a few screws missing :D

RaZeDaHeLL
February 3rd, 2012, 08:23 AM
I just called and they said bolts were missing from the exhaust.... So I guess it was not that big of a problem. When he said I had bolts missing I thought he meant from the fairing or something.

NDspd
February 3rd, 2012, 11:49 AM
I just called and they said bolts were missing from the exhaust.... So I guess it was not that big of a problem. When he said I had bolts missing I thought he meant from the fairing or something.

Oh ok, no biggy.

toua70
July 9th, 2012, 09:10 AM
has anyone else experienced this? As of late, this has been happening to me on cold start ups. In the morning when I go to work, as I turn on the bike, there will be a LOUD pop (almost sounds like a gun shot) where the exhaust is... wtf could be causing this to happen? :confused:

PsHYk
July 9th, 2012, 09:15 AM
do you have a stock exhaust or aftermarket? i dont really think that matters but it might plus i think its something about when you turn it off and fuel stays in the carbs or something so when you go to start it it burns that off and makes that popping sound...
p.s mine does that too and i dont worry about it too much...:thumbup:
im a noob though so maybe i should worry... :(

toua70
July 9th, 2012, 09:20 AM
do you have a stock exhaust or aftermarket? i dont really think that matters but it might plus i think its something about when you turn it off and fuel stays in the carbs or something so when you go to start it it burns that off and makes that popping sound...
p.s mine does that too and i dont worry about it too much...:thumbup:
im a noob though so maybe i should worry... :(

hmm that sort of makes sense lol - i have a danmoto GP CF exhaust. It scares the sh!t outta me though

broilmebk
July 9th, 2012, 09:36 AM
http://www.ninjette.org/forums/showthread.php?t=15025

Mine did once with the stock exhaust. I think it's twice now with my danmoto.

PsHYk
July 9th, 2012, 09:43 AM
http://www.ninjette.org/forums/showthread.php?t=15025

Mine did once with the stock exhaust. I think it's twice now with my danmoto.

was just gonna send him to that... XD
theres a video in here somewhere too i just cant find it... =/
seems to be normal though...:thumbup:

Alex
July 9th, 2012, 09:45 AM
/merged

alex.s
July 9th, 2012, 10:31 AM
when you first start cranking it puts gas through the system and it flows out the exhaust until the first fire when it sends hot gas out which ignites the remaining gas vapor that was in the exhaust from before it fired. maybe more backfire on startup means your exhaust pipe has more volume to hold more gas vapors? maybe it means your jetting is rich when its cold. who knows, not me.

lindasninja
September 10th, 2012, 08:12 AM
Was wondering if anyone can tell me if they were totally sure you haven’t touched the throttle grip? First time it happened my son was ‘helping me’ check the oil and said wow this grip doesn’t go round that far! Yep he’s sacked! Left it to sit for a few hours in the ‘hope’ the fuel would drain, but no, sure enough bang! Took me an hour to go check, was so expecting to see aluminum shrapnel, started like a charm!

Has happened perhaps 5 times in 2700ks and only at start up! But I always have to move mine before I start her, anyone 100% sure they haven’t touched a throttle? As I was thinking this was the reason, for the backfire not just a random thing? Like after stoping the bike you give it a small twist while getting off or moving it? As I was almost sure it was extra fuel ??? Poor hubby was right behind the last time, and got the full ‘detonation’ wasn’t at all impressed, and didn’t have his helmet on either!! Woops! Totally 100% sure it’s out the pipe!

dubojr1
September 10th, 2012, 08:25 AM
I am 100% sure.

lindasninja
September 10th, 2012, 08:29 AM
Thanks, now I know it’s totally random and going to do it somewhere really choice!

bdavison
September 10th, 2012, 08:45 AM
Look guys, I know why this happens.

When you came home the previous night on the bike, you pulled into the driveway, and hit the kill switch.

That is why.

If you pull into the driveway with even with a little bit of throttle and then hit the kill switch, it will load up a bit of unburnt fuel/vapor into the exhaust header.

The next morning when you hit the starter button, and that first burst of hot exhaust gas hits the vapor in the exhaust...it goes BOOM.

You can repeat this scenario....
Hop on your bike, Rev it up a bit, and hit the kill switch, then flip it back and hit the starter....PLUG YOUR EARS...cause its gonna go BOOM big time.

If you dont want it to pop every morning, then dont use the kill switch to stop the engine when you any bit of throttle in it.

Sound Wave
September 10th, 2012, 09:35 AM
i never used to use the kill switch and it would still backfire every now and then. i'd let it idle a bit after the ride before shutting off the engine... didn't matter. totally random and when i least expected it.

lindasninja
September 10th, 2012, 10:29 AM
I always thought you hit the kill switch when you were about to hit something! And the Kill switch is a bit nasty on the bike, maybe used it like 10 times to see if it worked, not crashed!? Also put in neutral when I get home, and idle it have to reverse in between cars, backwards then through a gate, usually get the angle right then, get off and turn of the bike, take helmet off and roll it to its home! I knew nothing at all, when I got my L’s so I did lots of reading, and apparently better for the engine to do the cool down thing? Go nice and gentle just a bit before you get home, and turn it off, after a few seconds of not moving like a cool down lap, but not idling too much as it heats the engine too much? Sorry think that might not help the idle theory!? Totally random again!

g21-30
September 11th, 2012, 04:06 AM
If you dont want it to pop every morning, then dont use the kill switch to stop the engine when you any bit of throttle in it.

Not! :eek:

I always use the ignition key to turn off the engine. You WILL get a backfire....sooner or later! :thumbup:

dubojr1
September 11th, 2012, 04:55 AM
Not! :eek:

I always use the ignition key to turn off the engine. You WILL get a backfire....sooner or later! :thumbup:

He speaketh the truth. There is NO known cause.

250rr
November 14th, 2012, 03:03 PM
Happened to me for the first time this morning. High 40's degrees. No throttle, full choke. As one of the previous replies pointed out, it sounds like a gun shot! Thank goodness for my ear plugs. :thumbup:

thomason2wheels
November 18th, 2012, 08:16 PM
Two weeks to the day! My bike had a healthy backfire at startup this afternoon. Lady a few houses down was working in her flower garden. It gave her a pretty good startle, So much for the thought that the CDI retrofit fixed it! I knew I shouldn't have mentioned it. :confused:

I know this is off topic, but did you notice a fuel economy improvement after backdating your cdi? Respond by pm if u like...thx.
Tom

thomason2wheels
November 18th, 2012, 08:25 PM
When you stop the engine the odds are good at some point you will do so in a way that leaves one cylinder with fuel vapor in it and unignited. Then when you hit the starterif the exhaust valvehappens to beopen when the plug fires, boom, you get a bigbang. Makes sense to me anyway. :Da

Corona
January 17th, 2013, 12:16 PM
I bought my bike used, the first backfire happened months after and it happened about 6 times within a month, after that I haven't had another, it's been about 3 months without it happening