July 23rd, 2015, 08:57 PM | #1 |
ninjette.org member
Name: Steve
Location: Spartanburg, SC
Join Date: Nov 2014 Motorcycle(s): EX250, Suzuki Savage, 76 Goldwing restoration project, 71 CB350, 73 Yamaha GT1, Posts: 73
|
Misfiring at low revs
I have noticed recently that when I turn a corner nice and slow, sometimes my bike misses on one cylinder a little before I speed back up. This is the only time it misses.
I checked my plugs tonight thinking it might be one of them. Both were gapped at .020 so I re-gapped at .025. Bike sounds a little better and seems like it might pull just a little harder. But, the low speed miss is still there. While I was looking around, I noticed that the PO had butted up the connections from the air box but didn't reconnect them. After spending all the time trying to get them on, I know why. That air box is some kind of torture device. I just hope I remember the combination to get it back on next time. Now, the miss, I'm thinking it must be carb related since the plugs made no difference. I have noticed that sometimes with no load like going slightly downhill and the engine is just turning freely, neither pulling or dragging, I hear one cylinder sputtering. I have been figuring this was carb related. What do you all think about this problem? A little info. 2005 Ninja 250, no mods, bone stock except the PO removed the baffles from the very back end of the mufflers, 14,400 miles on it. Just put gas in it 5 days ago and down to about half a tank now. Always run reserve a couple minutes after filling up, so it shouldn't be a water problem. Nothing but gas came from the bowls when I drained them to see if there was water. |
|
July 23rd, 2015, 11:46 PM | #2 |
in your machine
Name: Scott
Location: Summer Shade, Ky.
Join Date: Oct 2014 Motorcycle(s): 98 Ninja 250/F12 aka ZX-2R "SERENITY", 91 Ninja 500/A5 aka ZX-5R "Phoenix", 84 Honda GL1200A "SIREN" Posts: A lot.
Blog Entries: 25
MOTM - Jun '17, May '16, Mar '15
|
Did you disassemble, cleaned the spark plug caps? Renew the ignition wire ends?
__________________________________________________
violente et ignorantia ZX-2R BLOG Twitter and Instagram = Ghostt_Scott I'm not here to change your mind, just to inform. |
|
July 24th, 2015, 04:15 AM | #3 |
ninjette.org member
Name: Steve
Location: Spartanburg, SC
Join Date: Nov 2014 Motorcycle(s): EX250, Suzuki Savage, 76 Goldwing restoration project, 71 CB350, 73 Yamaha GT1, Posts: 73
|
I did not. Are they known to be a problem on this bike?
The caps fit nice and tight. The wires look good, no scrapes or anything and fit nice and tight at both ends. I'll pull the tank and take a look at the caps and renew the wire ends today just to make sure. |
|
July 24th, 2015, 04:36 AM | #4 | |
in your machine
Name: Scott
Location: Summer Shade, Ky.
Join Date: Oct 2014 Motorcycle(s): 98 Ninja 250/F12 aka ZX-2R "SERENITY", 91 Ninja 500/A5 aka ZX-5R "Phoenix", 84 Honda GL1200A "SIREN" Posts: A lot.
Blog Entries: 25
MOTM - Jun '17, May '16, Mar '15
|
Make sure you disassemble the caps, and clean them, and yes the caps get cruddy.
Here my write-up, Quote:
Here's some pictures that might be helpful. I took these when I replaced the wires themselves, as it was a good time for a write-up, and the wires were OEM from 1998. Wires are just 7mm copper core, with clear silicone jacket
__________________________________________________
violente et ignorantia ZX-2R BLOG Twitter and Instagram = Ghostt_Scott I'm not here to change your mind, just to inform. |
|
1 out of 1 members found this post helpful. |
July 24th, 2015, 09:05 PM | #6 |
in your machine
Name: Scott
Location: Summer Shade, Ky.
Join Date: Oct 2014 Motorcycle(s): 98 Ninja 250/F12 aka ZX-2R "SERENITY", 91 Ninja 500/A5 aka ZX-5R "Phoenix", 84 Honda GL1200A "SIREN" Posts: A lot.
Blog Entries: 25
MOTM - Jun '17, May '16, Mar '15
|
@xXecuterXx2 just doing my part, and I love being able to help, and having the time to do it.
I remember back in the day learning things was different before the internet, it's an awesome tool for learning, and helping out. Sharing my knowledge and experience with anyone willing to read it, and hopefully saving them time and money, and most importantly downtime.
__________________________________________________
violente et ignorantia ZX-2R BLOG Twitter and Instagram = Ghostt_Scott I'm not here to change your mind, just to inform. |
|
July 24th, 2015, 09:55 PM | #7 |
ninjette.org member
Name: Steve
Location: Spartanburg, SC
Join Date: Nov 2014 Motorcycle(s): EX250, Suzuki Savage, 76 Goldwing restoration project, 71 CB350, 73 Yamaha GT1, Posts: 73
|
So, I didn't have a chance today to check it out. I'll try to get to it tomorrow between driving the wife to work and going to the big meet in Chesnee. If not, I will try to get it sunday.
You mean you can actually still buy spark plug wire with actual wire in it? So, how come we have a resistor plug cap and a resistor plug. Why are we trying to reduce the voltage to the spark plug? I always thought the idea was to get the voltage and current to the electrode. Resistors do just the opposite. I realize that resistors do help cut ignition noise in the radio but how many of our bikes have radios on them? Thanks for the pics. That sure gives a good idea of what to do and look for when I do it. |
|
July 25th, 2015, 12:53 AM | #8 | |
ChocolateMilk Addict
Name: Maurice
Location: McDonough
Join Date: Mar 2015 Motorcycle(s): '05 EX-250 "Kallie" 85 KLT 110 ATC "Murdock" Posts: 329
|
Quote:
|
|
1 out of 1 members found this post helpful. |
July 25th, 2015, 02:02 AM | #9 | |
in your machine
Name: Scott
Location: Summer Shade, Ky.
Join Date: Oct 2014 Motorcycle(s): 98 Ninja 250/F12 aka ZX-2R "SERENITY", 91 Ninja 500/A5 aka ZX-5R "Phoenix", 84 Honda GL1200A "SIREN" Posts: A lot.
Blog Entries: 25
MOTM - Jun '17, May '16, Mar '15
|
A Brief Explanation of How a Spark Plug Works
Okay here's the answers you seek,
Quote:
__________________________________________________
violente et ignorantia ZX-2R BLOG Twitter and Instagram = Ghostt_Scott I'm not here to change your mind, just to inform. |
|
|
July 27th, 2015, 05:57 PM | #10 |
ran when parked
Name: Katie
Location: DC/MD
Join Date: Aug 2013 Motorcycle(s): Freeride 250R, KLX250SF, mopeds Posts: A lot.
MOTM - Sep '17, Dec '14
|
my 650r does this once in awhile. I don't feel like messing with it. let me know what the solution to your problem is and I might do the same thing lol.
__________________________________________________
Instagram: @katie.baden |
|
August 13th, 2015, 07:51 PM | #11 |
ninjette.org member
Name: Steve
Location: Spartanburg, SC
Join Date: Nov 2014 Motorcycle(s): EX250, Suzuki Savage, 76 Goldwing restoration project, 71 CB350, 73 Yamaha GT1, Posts: 73
|
Here's an update on what's going on.
I have removed and gone through the carbs. They were pristine inside. No crud, no discoloration, no marks where anyone had ever been in before. Diaphrams and slide work great. All jets and passages clean and passing air with no problem. Chokes work as they should and slide is moving freely. I always use real gas, no alcohol. I have removed and checked / cleaned the plug caps and wires to the coils. I found nothing wrong there either. Everything looked pristine with dust on the outside of the items. I did notice that the PO had installed Autolite plugs. According to Advance Auto they are the proper cross reference. I have NEVER had a good Autolite plug. They always cause misfires. I closed the gaps a little on the plugs from the factory specs and it runs better but the miss is still there, just not as bad. I'll be ordering the proper NGK plugs for it soon and see if that fixes the problem. One other thing I noticed, since this started, I never have to choke it. Before, I always had to choke it to get it started, even if it was 85 deg. In fact, if I choke it now, it usually won't start. |
|
August 13th, 2015, 08:24 PM | #12 |
ChocolateMilk Addict
Name: Maurice
Location: McDonough
Join Date: Mar 2015 Motorcycle(s): '05 EX-250 "Kallie" 85 KLT 110 ATC "Murdock" Posts: 329
|
Autolite is trash, those NGK's oughta do you nice, keep us posted.
|
|
August 14th, 2015, 01:58 PM | #13 |
Rev Limiter
Name: Jay
Location: WI
Join Date: Jul 2013 Motorcycle(s): '06 SV650n, '00 Derbi GPR, '64 CA77 Dream 305, '70 CL450 Scrambler, numerous dirt bikes Posts: A lot.
MOTM - Jun '18, Oct '16
|
How about the idle mixture screws - where are those set?
Because you don't need to use choke, it would suggest the idle circuit is adjusted too rich for whatever reason. |
|
August 15th, 2015, 08:38 AM | #14 |
ninjette.org member
Name: Steve
Location: Spartanburg, SC
Join Date: Nov 2014 Motorcycle(s): EX250, Suzuki Savage, 76 Goldwing restoration project, 71 CB350, 73 Yamaha GT1, Posts: 73
|
The caps are still on the mixture screws. It was late and I didn't remove them. Wondering why the idle would richen that much. I have always had to choke it when cold starting.
I also noticed something strange. Probably something stupid on my part. Ever since I bought the bike I have gotten 62-63 mpg my last tank was 86 mpg. I am currently assuming I didn't reset the trip meter when I refuelled or something. I will check mileage again when I empty this tank and see if it's still different. A close to 30% change in fuel economy without any corresponding change in fuel, bike, or riding style just doesn't make sense. Hey, that's just about the time I noticed that the airbox wasn't properly connected to the carbs and reconnected it. Could it make that much difference? |
|
August 15th, 2015, 02:04 PM | #15 |
in your machine
Name: Scott
Location: Summer Shade, Ky.
Join Date: Oct 2014 Motorcycle(s): 98 Ninja 250/F12 aka ZX-2R "SERENITY", 91 Ninja 500/A5 aka ZX-5R "Phoenix", 84 Honda GL1200A "SIREN" Posts: A lot.
Blog Entries: 25
MOTM - Jun '17, May '16, Mar '15
|
If the tamper caps are still on the carburetors, then you couldn't have cleaned the idle circuit.
Did you physical remove the idle and main jets? And main jet holders? Did you verify all the fuel circuits were clear with a air compressor? Set the float height? Etc...... http://faq.ninja250.org/wiki/Changin...rands_to_avoid NGK Iridium IX® plugs are the way to go personally, I run them in both the Ninjette and EX. http://www.ngksparkplugs.com/product.../iridiumix.asp NGK (7669) CR8HIX Iridium IX Spark Plug, Pack of 1 https://www.amazon.com/dp/B000HDF852..._3P6Zvb2PBX9FX
__________________________________________________
violente et ignorantia ZX-2R BLOG Twitter and Instagram = Ghostt_Scott I'm not here to change your mind, just to inform. |
|
August 15th, 2015, 09:25 PM | #16 |
ninjette.org member
Name: Steve
Location: Spartanburg, SC
Join Date: Nov 2014 Motorcycle(s): EX250, Suzuki Savage, 76 Goldwing restoration project, 71 CB350, 73 Yamaha GT1, Posts: 73
|
I removed all jets and verified they were clean, jet holders as well. All circuits flow air just fine. The idle circuits flow air just fine from the jet opening out the little hole. Both sides flow the same. Although much harder to check, they do flow air back to the jet opening as well. You can get a huge amount of air through those main jets even if they are actually quite small. Float needles and seats look great.
Float height was checked according to this http://faq.ninja250.org/wiki/How_do_..._the_floats%3F They are both at exactly 17mm and no fuel in either of the floats. This isn't my first rodeo with carbs. I've had bikes with carbs for the last 40 years. I've cleaned, adjusted, made jets, rigged, soldered, patched, just about anything you can do with a carb on a bike, I've done it. Given that everything inside the carbs is pristine, no dust, dirt, goo, rust, discoloration even, jets are open, all passages flow, diaphrams and slides work well, floats and needles are fine, I don't believe there is anything wrong in the carbs. It feels and acts more like dirty points or a bad condenser on a real ignition system. If you feel it's imperative that the mixture screws be removed even though the circuits flow the same amount of air in each carb, I'll pull them and do it just to make sure. I was thinking very seriously about the iridium plugs. I've heard so much good about them and very little bad. |
|
August 15th, 2015, 09:35 PM | #17 |
in your machine
Name: Scott
Location: Summer Shade, Ky.
Join Date: Oct 2014 Motorcycle(s): 98 Ninja 250/F12 aka ZX-2R "SERENITY", 91 Ninja 500/A5 aka ZX-5R "Phoenix", 84 Honda GL1200A "SIREN" Posts: A lot.
Blog Entries: 25
MOTM - Jun '17, May '16, Mar '15
|
I personally remove the idle mixture screws for cleaning, and verify that the fuel circuits are clear with an air compressor, I also replace the O-rings on the idle mixture screws.
Sorry if I misjudged your abilities, but you've seen plenty of posts like this one, from noobs.
__________________________________________________
violente et ignorantia ZX-2R BLOG Twitter and Instagram = Ghostt_Scott I'm not here to change your mind, just to inform. |
|
August 16th, 2015, 10:37 AM | #18 |
ninjette.org member
Name: Steve
Location: Spartanburg, SC
Join Date: Nov 2014 Motorcycle(s): EX250, Suzuki Savage, 76 Goldwing restoration project, 71 CB350, 73 Yamaha GT1, Posts: 73
|
I have and have seen lots of times when something that really should have been done wasn't. That's why I asked if you thought it was imperative, I would do it.
Although I've had lots of experience with carbs, this bike and its carbs are new to me. There can always be a gotcha hidden somewhere. Any ideas about the fuel economy? I just can't believe that I didn't do something to fudge that calculation somehow. I've never heard of a 30% increase with nothing being done to prompt it. And, a 30% increase is very hard to get no matter what. I always use the same pump and fill just to the bottom of the little tube in the filler hole. Last fill up was 3.07 gallons and 288 miles on the trip meter. My bad, that figures to 93mpg...no way...I have to have done something wrong like forget to reset the trip meter or something. That kind of mileage outdoes my little 50cc scooter by a good bit. I haven't noticed any performance difference other than the little misses at around 2500 to 3000. Power is still fine, same pull is still there. No funny noises other than the clutch basket rattle. |
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
[motorcyclemonster] - Show Low, AZ - Hi-Low in Show Low Jun 21, 2014 | Ninjette Newsbot | Motorcycling News | 0 | April 23rd, 2014 03:10 PM |
|
|