Losing power, top speed is ~70 at 9,000rpm, WHAT'S GOING ON???

[Ninjettepgh]

Hello all

Disclaimer: I am an extreme newbie and this is my first bike so please talk to me like i'm an idiot!

The Problem:
Lately I've started to lose power on my bike especially at high speeds. I've also realized it kinda...hmm..."sputters"? Almost like its hesitating. Nothing toooo major but definitely not normal. I've read of other forums that say their ninjas go 80-90.....what?! I'm on my last gear at 9,000rpms and i feel like its not wanting to go beyond 70-75 haha.

Background Info:
I ride all year round...and it's Pittsburgh, so the bike has certainly taken a beating since I bought last september. I'm by no means mechanically inclined, but I have managed to replace the clutch cable, change the oil, air filter to a KN filter, brakes, and put on a 2 brothers exhaust. But, the thought of cleaning and syncing (what's that mean?) the carbs frighten me. I'm ridiculously poor so taking it to a shop to clean the carbs is out of the question. Also, i did replace spark plugs a couple months ago and didn't have the gap tool, but assumed it was spaced accordingly already? I know, i'm stupid. Would that little tiny detail cause this?

I try to keep up on maintenance but again, i'm not the most savy motorcyclist.

PLEASE, any advice would be appreciated. I'm probably missing some info, but ask questions, i'll try to respond. I feel so dumb

[CC Cowboy]

Originally Posted by PGHninjette

Hello all

Disclaimer: I am an extreme newbie and this is my first bike so please talk to me like i'm an idiot!

The Problem:
Lately I've started to lose power on my bike especially at high speeds. I've also realized it kinda...hmm..."sputters"? Almost like its hesitating. Nothing toooo major but definitely not normal. I've read of other forums that say their ninjas go 80-90.....what?! I'm on my last gear at 9,000rpms and i feel like its not wanting to go beyond 70-75 haha.

Background Info:
I ride all year round...and it's Pittsburgh, so the bike has certainly taken a beating since I bought last september. I'm by no means mechanically inclined, but I have managed to replace the clutch cable, change the oil, air filter to a KN filter, brakes, and put on a 2 brothers exhaust. But, the thought of cleaning and syncing (what's that mean?) the carbs frighten me. I'm ridiculously poor so taking it to a shop to clean the carbs is out of the question. Also, i did replace spark plugs a couple months ago and didn't have the gap tool, but assumed it was spaced accordingly already? I know, i'm stupid. Would that little tiny detail cause this?

I try to keep up on maintenance but again, i'm not the most savy motorcyclist.

PLEASE, any advice would be appreciated. I'm probably missing some info, but ask questions, i'll try to respond. I feel so dumb :confused:

You are way above my level of mechanical know how.

You might wanna check the thingy that makes the bike go faster. Maybe it isn't adjusted right.

[Ninjettepgh]

haha! "the thingy that makes the bike go faster..."???

And don't let that stuff deceive you, I've only been able to change all those things because of Youtube and forums on this site.

[THE BIG SITT]

I'd check the air filter

[Ninjettepgh]

I just changed the air filter to the K&N one literally 2 days ago. What could I have done wrong?
I took the stock foam one out, broke the white frame and took it out, put the K&N one on the air box cover, tightened with the clamps and put it back in...

[Coolbpf]

Originally Posted by THE BIG SITT

I'd check the air filter

I was going to say the same thing. I replaced mine and wow what a difference. Does your bike idle at 1.5-2k rpms? And when i'm in 6th gear I get my ninja to go 70 at about 9k rpms too... So It's not really all that bad. The people who are going 80-90 are redlining every one of the gears up to 6th... But just riding normally 9k at 70 mph sounds pretty good to me for a 250!

[Ninjettepgh]

Ok I feel better about that but... I still feel like it was going faster before... And the whole sputtering thing?...

[Yasko]

With the 15t front, my 07 runs 80mph at 9krpm sitting up. I'm 5'10" 180lbs.

My bike will top out at 92mph on my gps.

[ninjamunky85]

You've replaced your air filter with one that flows more air, and added an aftermarket exhaust, which also flows more air. So you've got all this extra air going through the motor, but no more fuel, meaning your running lean. These bikes are already jetted on the lean side from the factory to make the EPA happy.

Anyway you need to re jet your carbs, or just put the stock air filter and exhaust back on. Good luck

[Ninjettepgh]

And I assume rejetting the carbs are a PITA?

[DaBlue1]

Does it sputter like it's starving for fuel? or does it feel more like a surge or hesitation?

What is the condition of your chain? How many miles on it?

[Ninjettepgh]

More like a hesitation and that it's holding back....
And the chain to be honest is ...well, should probably be changed. Would this really contribute to this problem? I don't know how many miles are on the chain but the bike itself is on 12,xxx.
Also... Would the gap spacing contribute to this?...

Thanks guys

[ninja_thresh_hold]

id do a jet kit, im not sure if it would make it gain top speed, but it sure as hell cant hurt.

[DaBlue1]

Originally Posted by PGHninjette

....the chain to be honest is ...well, should probably be changed. Would this really contribute to this problem?

Yeap! You may want to pay attention to the condition of the sprockets as well.

I doubt the gap in the plugs is causing your issue your describe, but get a spark plug gapper just to double check the gap and for future plug changes.

When was the last valve adjustment done? At 12k miles, you are due for one.

It also wouldn't hurt to put some Seafoam or Star Tron Fuel Treatment in the fuel tank to help clean the carbs a little.

[ninjamunky85]

Originally Posted by PGHninjette

And I assume rejetting the carbs are a PITA?

Yes and no. If you've ever taken the carbs off to clean them then replacing the jets is easy. Getting the correct jetting however, is not easy. There is no set formula for which jets to use. Each bike is different, so it's really just a trial and error process. It's easier if you have access to a dyno, so you can see the air/fuel ratio through the RPM range.

This is why I've kept the exhaust stock on my bike. It's not worth the trouble for the small gain in performance on the 250.

BTW, my bike still pulls hard at 90 in 5th gear. I'm running a 15/42 sprocket setup.

[alex.s]

Originally Posted by CC Cowboy

You are way above my level of mechanical know how.

You might wanna check the thingy that makes the bike go faster. Maybe it isn't adjusted right.

its late. i'm reading this in my living room. i laughed for about 5 minutes after reading your post. the neighbors started banging on the wall so i figured i would congratulate you. you woke up my neighbors

[Ninjettepgh]

So...the conclusion is i should probably get a jet kit?

anyone have a good resource and teaching a complete newby on how to do this?

Thanks

[7oxSin]

i rebuilt the carbs on my first 250 12 times and could never get it right, when it comes to re jetting and syncing ur carbs i would pay a shop 60 bucks. also what rpms are you shifting at? ive got my 03 ninja 250 up to about 103 mph and the only thing i have on it is a full muzzy.

[Ninjettepgh]

$60?! That's it?

I'm shifting around 6-7 for 1st gear,
2nd and 3rd about 7ish
and 4th and 5th around 9
anymore than that and i feel like im pushing it too much...but then again...im a complete idiot on this stuff

[7oxSin]

Originally Posted by PGHninjette

$60?! That's it?

I'm shifting around 6-7 for 1st gear,
2nd and 3rd about 7ish
and 4th and 5th around 9
anymore than that and i feel like im pushing it too much...but then again...im a complete idiot on this stuff

u can take ur ninja up to 12k when u shift, if u shift too low like ur doing u will not have any where to go when u are in ur top gear, and that will result in a very low top speed. just dont take it past 12 cuz they ****ed up and put the redline at 14 when it needed to be at 12. and 60$ is what a local shop quoted me, if u go to a dealer they will rape u like always.

[Mocha Man]

Originally Posted by ninjamunky85

Yes and no. If you've ever taken the carbs off to clean them then replacing the jets is easy. Getting the correct jetting however, is not easy. There is no set formula for which jets to use. Each bike is different, so it's really just a trial and error process. It's easier if you have access to a dyno, so you can see the air/fuel ratio through the RPM range.

This is why I've kept the exhaust stock on my bike. It's not worth the trouble for the small gain in performance on the 250.

BTW, my bike still pulls hard at 90 in 5th gear. I'm running a 15/42 sprocket setup.

My answer is "yes!" Unless you cut the battery holder from the air box, getting it back into the frame is nearly impossible. Other than that, though, syncing the carbs just takes a good eye and lots of patience. It's really not all too difficult to do, though.

[ninjamunky85]

I'm shifting around 6-7 for 1st gear,
2nd and 3rd about 7ish
and 4th and 5th around 9
anymore than that and i feel like im pushing it too much...but then again...im a complete idiot on this stuff

As long as your not redlining it for extended periods of time you aren't hurting anything. It's the ninjette, it's meant to be revved, that's part of the fun.

Peak HP doesn't come until about 12.5k RPM's so if your going for max speed, that's where you should be shifting.

[flynjay]

Originally Posted by PGHninjette

Hello all

Disclaimer: I am an extreme newbie and this is my first bike so please talk to me like i'm an idiot!

The Problem:
Lately I've started to lose power on my bike especially at high speeds. I've also realized it kinda...hmm..."sputters"? Almost like its hesitating. Nothing toooo major but definitely not normal. I've read of other forums that say their ninjas go 80-90.....what?! I'm on my last gear at 9,000rpms and i feel like its not wanting to go beyond 70-75 haha.

Background Info:
I ride all year round...and it's Pittsburgh, so the bike has certainly taken a beating since I bought last september. I'm by no means mechanically inclined, but I have managed to replace the clutch cable, change the oil, air filter to a KN filter, brakes, and put on a 2 brothers exhaust. But, the thought of cleaning and syncing (what's that mean?) the carbs frighten me. I'm ridiculously poor so taking it to a shop to clean the carbs is out of the question. Also, i did replace spark plugs a couple months ago and didn't have the gap tool, but assumed it was spaced accordingly already? I know, i'm stupid. Would that little tiny detail cause this?

I try to keep up on maintenance but again, i'm not the most savy motorcyclist.

PLEASE, any advice would be appreciated. I'm probably missing some info, but ask questions, i'll try to respond. I feel so dumb

When was the last time you adjusted the valves?

[choneofakind]

Originally Posted by 7oxSin

u can take ur ninja up to 12k when u shift, if u shift too low like ur doing u will not have any where to go when u are in ur top gear, and that will result in a very low top speed. just dont take it past 12 cuz they ****ed up and put the redline at 14 when it needed to be at 12.

pfft lolwut?? They originally had the limiter cut in at 15000 then in 95ish they changed the limiter to 14500 because of oil delivery when held at high rpms for extended periods of time, aka loooong straights at tracks. The new bikes have a 13500 rpm red line, and I'm not sure when the limiter cuts in. But what I'm trying to say here is idk where you pulled 12000 from, but unless you're holding the bike at redline for and hour at a time, don't worry about revving the crap out of the engine once it's fully warmed up. The power band of a stock bike peaks around 12500, so rev it when needed.
Posted via Mobile Device

[7oxSin]

Originally Posted by choneofakind

pfft lolwut?? They originally had the limiter cut in at 15000 then in 95ish they changed the limiter to 14500 because of oil delivery when held at high rpms for extended periods of time, aka loooong straights at tracks. The new bikes have a 13500 rpm red line, and I'm not sure when the limiter cuts in. But what I'm trying to say here is idk where you pulled 12000 from, but unless you're holding the bike at redline for and hour at a time, don't worry about revving the crap out of the engine once it's fully warmed up. The power band of a stock bike peaks around 12500, so rev it when needed.
Posted via Mobile Device

i was told by a bike mechanic that also races 250s in a little function down at the track that you shouldn't take the 1st gen 250s past 12k when shifting because it was bad for the bike. he then said that they put 14k red line on the tachometer but should have put the red line at 12k. ive known this guy for 4 years, he has been racing for at least 10 years and has been a motorcycle mechanic for alot longer then that. so i take his word as fact not to mention there seems to be other members who share this point of view,

ninjamunky85

Peak HP doesn't come until about 12.5k RPM's so if your going for max speed, that's where you should be shifting.

[alex.s]

my 6th gear will take me from 35mph to bouuncing off the rev limiter (12.7k) in 6th which with my gearing is 102mph.

[dirty nasty]

Wait. You bought an aftermarket pipe and introduced more air into the bike by installing K&N filters and didn't even re-jet? If you want a machine that you can reliably ride every day then I'd recommend going back to the stock setup. If you insist on keeping your setup for street use, then I insist you call up some of these companies about jetting. Look up Dyno Jet. They make a Stage 1 and 3 kit designed to work with modified intake and exhaust systems.

You need a feeler gauge to gap your plus. In my experience they've always been gapped correctly from the dealer. However, DO NOT TRUST THIS EVER! Check the gap every single time on every single plug you change.

I second checking your valve clearances. It can't hurt.

Cleaning the carbs is easy. It's just a matter of paying attention, reading good sources of info, and taking your time. Jetting is trial and error. If you have K&N filters with no air box, then removing them is easy. If you have the stock airbox in place, you need to pull the rear wheel off, pull out all the rear fenders, then pull the airbox out through the rear of the bike. Then, cut the battery tray off, being careful not to cut into the intake side of the airbox. Put it all back together. Now when you go to pull your carbs off all you need to do is remove the battery and 2 bolts and peel the airbox back instead of taking the bike half-way apart.

[JLinde1339]

The hesitation its definitely a lean condition. I have the same filter with 110 mains and stock exhaust. Airbox delete. I thot my chain was causing the hesitation. It wasn't. Cheap and dirty fix? I ran duct tape around the aire filter to restrict the air intake. Practically have it covered. Cut about 4 half-inch slits in the tape on each side. Problem solved.

[alex.s]

Originally Posted by JLinde1339

I ran duct tape around the aire filter to restrict the air intake. Practically have it covered. Cut about 4 half-inch slits in the tape on each side. Problem solved.

ahhahahaha

next someone is going to say just run with the choke on

[JLinde1339]

Originally Posted by alex.s

next someone is going to say just run with the choke on

That didn't work either.

[Kevin2109]

Originally Posted by JLinde1339

The hesitation its definitely a lean condition. I have the same filter with 110 mains and stock exhaust. Airbox delete. I thot my chain was causing the hesitation. It wasn't. Cheap and dirty fix? I ran duct tape around the aire filter to restrict the air intake. Practically have it covered. Cut about 4 half-inch slits in the tape on each side. Problem solved.

hahahahahahahahahahahahahaha

[dirty nasty]

Originally Posted by Kevin2109

hahahahahahahahahahahahahaha

I've seen people do similar modifications to Honda CBs with the Keihin CV carbs with the heavy aluminum "puck" slides to increase vacuum in order for them to work with the airbox removed. However, their mods appeared to be much cleaner than "wrapping duct tape around it".

I think that it's just much easier to use the stock setup than re-jetting for a street machine. Think about it, why? The bike can already very easily exceed the speed limit in stock form. Quicker than most cages to boot. Why do you need to make it unreliable, more complicated, more expensive, for such little gain that you can't legally use? It just blows my mind that people spend such great money on modifying their machines, yet you never see them at the track. You do usually see them pulled over getting arrested for street racing though!

[Kevin2109]

Originally Posted by dirty nasty

I've seen people do similar modifications to Honda CBs with the Keihin CV carbs with the heavy aluminum "puck" slides to increase vacuum in order for them to work with the airbox removed. However, their mods appeared to be much cleaner than "wrapping duct tape around it".

I think that it's just much easier to use the stock setup than re-jetting for a street machine. Think about it, why? The bike can already very easily exceed the speed limit in stock form. Quicker than most cages to boot. Why do you need to make it unreliable, more complicated, more expensive, for such little gain that you can't legally use? It just blows my mind that people spend such great money on modifying their machines, yet you never see them at the track. You do usually see them pulled over getting arrested for street racing though!

Duct tape is fine for diagnosing a problem, not the fix. That would be like wearing a ton of make up to hide your herpes, you still have herpes!


Then why ever buy a 600 or a 1000? Why not just have a ruckus? (which are badass btw) Why have a bigger house then you need? Its human nature to not leave **** alone, its fun, and gives us something to do. I modded the living **** out of my street 250 but sadly never took it to the track. My 636 puts down more power then 4 stock 250's, I love it on the street and on the track.

[alex.s]

Originally Posted by Kevin2109

Duct tape is fine for diagnosing a problem, not the fix. That would be like wearing a ton of make up to hide your herpes, you still have herpes!

is there something you forgot to tell me, kevin

[Kevin2109]

Originally Posted by alex.s

is there something you forgot to tell me, kevin

yolo

[dirty nasty]

Originally Posted by Kevin2109

Duct tape is fine for diagnosing a problem, not the fix. That would be like wearing a ton of make up to hide your herpes, you still have herpes!


Then why ever buy a 600 or a 1000? Why not just have a ruckus? (which are badass btw) Why have a bigger house then you need? Its human nature to not leave **** alone, its fun, and gives us something to do. I modded the living **** out of my street 250 but sadly never took it to the track. My 636 puts down more power then 4 stock 250's, I love it on the street and on the track.

You're missing the point. If it ain't broke, don't break it with stupid modifications that won't help you whatsoever on the street. Or at least take the necessary steps so you don't get what we've got here.

[TBC]

Off topic, but OP - join us over in the Pittsburgh thread .

[JLinde1339]

Did I not say it was a quick and dirty fix? Pretty sure I did...

Originally Posted by JLinde1339

...Cheap and dirty fix? I ran duct tape around the aire filter...

Oh look, I did. I even left the OE-style 'aire' swypo that my phone thinks is a word. So, what's the issue again?

[alex.s]

issue is; thats not a fix. its a crutch to kinda get it close to what it should be. the fix is to do it correctly.

[JLinde1339]

I offered a solution to the OPs problem. I had the same symptoms, and offered what I did to remedy it so it would run the way I wanted it to. I have yet to read a 'correct' solution to the problem. Ideally, I would fab a fiberglass shield to put around the filter, with a vent like on a bbq grill to control the flow for varying atmospheric conditions. Or I could keep buying bigger jets and hope that thru trial and error, I eventually come across the right size. Would those be correct ways to solve the problem? Maybe. But the weather's awesome, and I want to get out and ride. Not tear down, rebuild, test, wash, rinse ,repeat. Zzzzzzzzzz.... So if anyone has a solution, post up. I'm all ears. I'm not crazy about duct tape on my filter myself, but it did the trick. And until I have the time and resources for a more permanent solution, thats how I'll be riding.