need some help. ive got an issue with my bike shutting down on me after higher rpm freeway driving or prolonged road driving. I have tested the rectifier which seems to be working fine (voltage output is between 13.5 and 15.5 volts).the carbs were just cleaned and it has been rejetted with a dyno jet stage 1 (the problem existed before the jetting). the fuel pump is delivering fuel (when tested on a stand with the hose off). the fuel pump evac lines are clean (but have been disconnected to help diagnose problem).

Basically it fires up strong and runs very strong for 10 mins or so then with bog down (on freeway mostly) and completly shuts off once the clutch is pulled in. It will fire up after i sit on the side of the road (and let it cool) for about 5 to 10 minutes but will run very poorly.
i cant figure it out. any suggestions?
thanks

 

Did you adjust the fuel mixture and do a carb synch according to specs? Are the hoses attached and secured? Air box and air filter clean? Battery holding charge? Connections to battery secured and in good shape? Is the idle rpm also to specs? I guess this is where I would start if you haven't already? Good luck.

 

thank you for the reply! yes, i had the dyno jet kit installed and adjusted at my local shop and it has been adjusted to spec. t(i have been assured). the hoses are attached and in great shape. the air box is spotless and clean (i cleaned it when i installed a new K&N filter). The battery is new and is fully charged and holds a charge just fine. the idle rpm is adjusted to spec (for california). this is why i am having such an issue.... i am perplexed by it.

maybe an electrical issue? sensor, wire or maybe spark plug wire short? i am uncertain.
anything i am not thinking of?

 

It might be an electrical problem,have you checked the ignition control module? After looking at the wiring harness nothing else seems like it could be the problem, try changing it out and seeing if that works.

 

Did you address this problem to your shop? If so what did they say?

Is the temperature high when it starts to act up?... does the fan kick on and then it starts bogging down?

Sorry to address your issue with questions but it sounds like your running strong until she starts to gets warmed up. If the fan starts kicking and then the problems starts I think it's an electrical issue. The battery might not be producing enough juice to run the rest of the bike. But you say that system is good so I'm stumped. If the problem does start when the fan kicks on then I wouldidlethe bike until the fan kicks on and check the voltage. Just a thought.

 

thanks again for the responses. i will look into some things this weekend. i dont know how the ECM could just fail when it warms up but be fine other times. It's a solid state module and i would think that if it went bad, it would be BAD and not work at all.... i will investigate that regardless though.

the shop didnt have time to really look into it because they had a bunch of things lined up in front of me and the bike would just sit for a few days before they would get to it. they also bill by the hour and who knows how long it will take to find the problem while on a heavily billed rate. i figured i would give it a shot and use them as a last resort.

the bike is not overheating. the fan's kick on and off normally and there is no significant power drop that would stall the bike out when the kick on at idle.

there is an ignition advancer installed on the bike, but i dont think that is a big factor in what is going on.

at least i can seek some comfort knowing i am not the only one who is stumped. thanks for your help though. i will be plugging away at it this weekend.

 

Mine would run great unless I slowed suddenly, then the bike would stall. Rapid decel from highway speeds to a sharp off-ramp corner, for example. It got to the point where a decel from street traffic speeds to a stop at a red light or stop sign and she'd stall on me. A carb sync made the problem go away immediately and not return. I know the shop did a sync, but that sure is what it sounds like.
On an unrelated note, your shop shouldn't charge you crazy labor for a diagnosis... how far are you from TN? My shop would hook you right up