I had my track bike out this weekend and bike ran awesome for first hr.After that it started getting a stumble anytime I'd get on the throttle had.The stumble would start around 6k and up.Below that bike ran normal.Any idea what could cause this?

 

power commander crapping out?

 

Maybe one of the coils is going bad?

 

How could I test the coil?I even thought it could be bad fuel so I ran the tank dry added new fuel and still did the same thing.

 

Has it done it again since you rode it last time? If it runs well again since the engine has cooled off, it could be a sign that one or more are on their way out, because it could mean once the bike gets hot hot, the coils start to intermittently misfire-which is a sign of a possible bad coil.

 

The bad thing is that this is my track bike and can't be ridden on the street.

 

Start it up and let it run. Take longer but shell get hot enough after 15-20 minutes.

 

It could also be plugs too.


Anytime you say "higher rpms, WOT, and after the engine is warm" makes me want to think ignition and start there.

Maybe check your FPR just to be sure (even though its in theory at it's least amount of bleed off at Hi RPMs), but I'd still guess ignition.

I'd tell you to swap the coils from your street 954 over to your track one - but that's a lot of work to do on an off-the-cuff guess.

 

I do have another set of coils that I can swap out and I'll check the plugs.This motor only has 13k miles.

 

I wouldn't guess it's the motor.

Hopefully your track bike is easy to tear into! I know it's a lot of work for a guess, but I'd have to think it's the ignition to start. Let us know as soon as your doing work on it.


I would suggest letting the bike idle for a while in your drive way (a few cycles of fan on-and-off), and then trying to ride the bike to an area where you can do a couple of higher rpm pulls to see if it's doing what it did at the track before you tear into it. I know it's not exactly legal to ride it, and again, I have no concept of where you live. If it's in the middle of a congested town, that plan is out...