stumbling bike

[FvnnyL3tt3r1ng]

Yesterday I was doing wheelies and after a couple my bike started acting like the carbs were fouled. At times I was only running 1 cylinder when in the low-band (under 5k) and even after getting up to speed it would stutter a lot. I pulled the carbs and did the best I could to clean them but they seemed fine and not clogged up or anything. I still can't pull the pilot jets... I rode it around for a little with the choke set to let the bike idle at 2k and it seemed to run like it would normally. Any ideas? After work I'm gonna check the fuel level in the bowls and possibly re clean the carbs. The floats and plungers( forgot the name) seem to be fine...

[EsrTek]

I'm no a wheelie guy, but I recall hearing that too vertical on wheelie can cause fuel starvation.

[choneofakind]

restraining myself from commenting on the wheelies.

How many miles on the spark plugs?

[FvnnyL3tt3r1ng]

Originally Posted by choneofakind

restraining myself from commenting on the wheelies.

How many miles on the spark plugs?

Less than 1000. Wheelies or die.

[csmith12]

Jar something loose when setting it down? Carb boot? Vac line?

[FvnnyL3tt3r1ng]

Originally Posted by csmith12

Jar something loose when setting it down? Carb boot? Vac line?

No and no

[choneofakind]

Have you run it since it started acting funny? Is it still acting up?

[FvnnyL3tt3r1ng]

Originally Posted by choneofakind

Have you run it since it started acting funny? Is it still acting up?

Yeah I ran it and it acted the same. pretty sure there is something lodged inside my pilot jet(s). How can I get those damn things out if they are being stubborn? I just sprayed wd40 in the passage where the screwdriver would go now I am waiting.....

[FvnnyL3tt3r1ng]

Ok got one out. You're not supposed to see light thru the center shaft of them like the main jets are you? They seem fine I really hope this isn't a timing issue

[csmith12]

YES! All the jets should allow free flow of gas through them.

[FvnnyL3tt3r1ng]

Originally Posted by csmith12

YES! All the jets should allow free flow of gas through them.

Saw a teeny tiny hole after I ran some guitar string through the one pilot jet I managed to remove. Bike still acts the same! I have to go full choke to start it and if I take the choke off it it will just die even after warm-up.... I hope my tensioner didn't come loose...and I hope I didn't blow a head gasket

[choneofakind]

If it's dying after choke, it's carb related. Just pull the carbs and clean all the jets and passages. Just cleaning the jets might or might not get everything.

[FvnnyL3tt3r1ng]

Originally Posted by choneofakind

If it's dying after choke, it's carb related. Just pull the carbs and clean all the jets and passages. Just cleaning the jets might or might not get everything.

I did this! Problem persists.....

[choneofakind]

Are any of your vacuum hoses leaking?

Does this video sound familiar at all? This is rojoracing53's video in response to another user btw.
http://www.ninjette.org/forums/showp...9&postcount=45

[FvnnyL3tt3r1ng]

Originally Posted by choneofakind

Are any of your vacuum hoses leaking?

Does this video sound familiar at all? This is rojoracing53's video in response to another user btw.
http://www.ninjette.org/forums/showp...9&postcount=45

I looked over the vacuum hoses and all seemed to be fine except for one. There is one that goes from one carb to the next right by the choke cable I believe that has a tiny slit in it. I wasn't sure if that was leaking I guess I should have tested it.

The video seemed to be pretty similar to what I am experiencing.

[choneofakind]

Wrap the slit in electrical tape really well to try and get it to seal a bit better. Does your condition get better?

If so, that's causing a leak and you need to replace that little piece of hose.

I think your wheelies and your bike issue are not related and the timing is purely coincidental.

[csmith12]

Sounds like he pinched the line setting it down most likely.

[FvnnyL3tt3r1ng]

Originally Posted by choneofakind

Wrap the slit in electrical tape really well to try and get it to seal a bit better. Does your condition get better?

If so, that's causing a leak and you need to replace that little piece of hose.

I think your wheelies and your bike issue are not related and the timing is purely coincidental.

I really hope so! Maybe the high engine speed forced the vacuum to break through...

[FvnnyL3tt3r1ng]

Originally Posted by csmith12

Sounds like he pinched the line setting it down most likely.

This question is a long shot but did you live in FL in the past?

[csmith12]

Yes sir, Tampa.

[FvnnyL3tt3r1ng]

Originally Posted by csmith12

Yes sir, Tampa.

Close....if you said West Palm Beach I would have been like

[csmith12]

I loved Tampa. I visited last year and wow, so much growth. I couldn't live there again. I would have to go farther south where it's no so crowded.

[FvnnyL3tt3r1ng]

I'll try the electrical tape test tomorrow and report back. I'll be pretty happy if its just a vacuum line. I'll do a mean wheelie just for chone.

[FvnnyL3tt3r1ng]

Wrapped with tape, problem persists. Recorded video, gonna post on Utube when I can. Did I mention when going wot the bike really drops and almost dies before catching up and running normal/close to normal acceleration

[FvnnyL3tt3r1ng]

Anybody real good with this bikes' carbs that can tell me which vacuum line I would need to look at if the choke runs fine? Could it be a pilot jet still even though I ran guitar string through them and sprayed plenty of cleaner and canned air?

[DaBlue1]

Originally Posted by FvnnyL3tt3r1ng

.... Did I mention when going wot the bike really drops and almost dies before catching up and running normal/close to normal acceleration

Any of these sound familiar?

Typical Lean Conditions:

- Poor acceleration; the engine feels flat.
- The engine won't respond when the throttle is snapped open, but it picks up speed as the throttle is closed. (A too-large main jet also mimics this symptom.)
- The engine runs hot, knocks, pings and overheats.
- The engine surges or hunts when cruising at part-throttle.
- Popping or spitting through the carb occurs when the throttle is opened. Or popping and spitting occurs through the pipe on deceleration with a closed throttle.
- The engine runs better in warm weather, worse in cool.
- Performance gets worse when the air filter is removed.

Typical Rich Conditions

- Engine acceleration is flat and uneven and loses that "crisp" feel.
- The engine "eight-strokes" as it loads up and skips combustion cycles.
- The engine idle is rough or lumpy, and the engine won't return to idle without "blipping" the throttle.
- The throttle needs to be open continuously to maintain acceleration.
- Black, sooty plugs, a sooty exhaust pipe and black smoke from the tailpipe that stinks of unburned fuel.
- Poor fuel economy.
- The engine works better when cold. Performance falls off as it warms up or the ambient temperature rises.
- Engine performance improves when the air cleaner is removed.

[FvnnyL3tt3r1ng]

Meh the first of the lean conditions fit but other than that not really

[FvnnyL3tt3r1ng]

If I'm driving it and I want to stop the bike I just go wide open throttle and the engine speed falls quickly and if I hold it long enough the bike will die.

[FvnnyL3tt3r1ng]

Is it possible this is a spark(plug)issue?

[FvnnyL3tt3r1ng]

Just grounded both plugs against the engine. This time without shocking myself. They're both fine.

[choneofakind]

I don't think this is a jetting issue if it just started happening randomly. Since you said you have spark, it's not the coils.

But some things to check:

• Is anything clogging the airbox?
• Do you have a leaky intake boot somewhere? Test with spraying anything flammable at individual parts of the intake.
• Are the connections to the coils connecting consistently to the coils?
• Are you sure that you were running on one cylinder at the time (was one header cooling down?)

[FvnnyL3tt3r1ng]

Originally Posted by choneofakind

I don't think this is a jetting issue if it just started happening randomly. Since you said you have spark, it's not the coils.

But some things to check:

• Is anything clogging the airbox?
• Do you have a leaky intake boot somewhere? Test with spraying anything flammable at individual parts of the intake.
• Are the connections to the coils connecting consistently to the coils?
• Are you sure that you were running on one cylinder at the time (was one header cooling down?)

The snorkel is clear and I run a k&n filter. The sparks were continuous if that's what u mean. Its been too long to say if I was running on one cylinder but as of now it doeant seem to be...
The intake boots seem solid they're so thick I couldn't imagine them being torn.

[choneofakind]

Are your battery connections solid? That causes funny things to happen if they're not.

Spray something at parts of the intake boots. If the idle races, you've found a leak.

[FvnnyL3tt3r1ng]

I'm really considering buying an extra carburetor for when situations like these arise. The value of being able to troubleshoot better would be worth it alone

[FvnnyL3tt3r1ng]

Originally Posted by choneofakind

Are your battery connections solid? That causes funny things to happen if they're not.

Spray something at parts of the intake boots. If the idle races, you've found a leak.

Connections are solid. Sprayed carb cleaner on boots...no fireworks

[FvnnyL3tt3r1ng]

Any idea what the symptoms of a skipped chain are?

[DaBlue1]

Originally Posted by FvnnyL3tt3r1ng

The snorkel is clear and I run a k&n filter.

How does the air filter look? Too much oil on an air filter can choke air flow.

Originally Posted by FvnnyL3tt3r1ng

Any idea what the symptoms of a skipped chain are?

If you are referring to the cam chain, skipped teeth could affect your timing.
Think your timing is off?

Also how is your fuel flow? Have any inline filters installed?

[FvnnyL3tt3r1ng]

Originally Posted by DaBlue1

How does the air filter look? Too much oil on an air filter can choke air flow.



If you are referring to the cam chain, skipped teeth could affect your timing.
Think your timing is off?

Also how is your fuel flow? Have any inline filters installed?

Well it seems the bike is running really lean because even if I turn the idle up a tad with the idle adjust the bike wants to almost die with the choke on fully. I have an inline fuel filter which is less than 6 months old. I checked the fuel level and it was fine in the bowls.

It's definitely a possibility my timing is off. I don't think there is anything else I can do to the carbs except to replace the hoses which are fine in my opinion.

[FvnnyL3tt3r1ng]

Link to original page on YouTube.

Here is the

Note: Both the bike and the ambient temp is warm.

[FvnnyL3tt3r1ng]

Originally Posted by DaBlue1

How does the air filter look? Too much oil on an air filter can choke air flow.



If you are referring to the cam chain, skipped teeth could affect your timing.
Think your timing is off?

Also how is your fuel flow? Have any inline filters installed?

As for the air filter being clogged. I noticed the crankcase vent hose wasnt attached to the airbox today so it couldn't have been on when the issue started (and yes I re attached it).