03 r6 - about 10000 rpm it kicks back to 6000... | GTAMotorcycle.com

03 r6 - about 10000 rpm it kicks back to 6000...

meme

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Buddy of mine and this one has me stumped. 03 r6 trackbike. Get it to about 10000rpm and it's almost like hitting the limiter (what it feels like riding) and engine kinda quits and retards us back to about 6.

So far I've switched out plugs, coils, tank and fuel pump and ECU with my stuff. Disconnected his power commander also and tried that. I have same bike without this problem. So I've eliminated spark, power, fuel and delivery (I think).

Stupid bikes! Anyone have another suggestion other than compression loss and a tired motor before he starts paying shop rates?
 
Nope, I switched my tank and pump into his and still did same thing.
 
This may be a stupid question as I am just learning about bike motors but know car motors well....
do bike motors have a knock sensors etc like cars?.... It's almost sounds like the motor is putting itself into "limp mode" because of some sort of sensor whether it be knock/iat/o2 sensor etc. The problem may not be with the ECU, but one of the wires from a sensor leading to the ECU.
 
Hmmm....i don't know either but something to ponder.

Also thought about the quick shifter last night, one thing he has that I don't.
 
does this in neutral? under low load? high load? Have you checked the ignition pickup?
 
Neutral yes. Light load - no idea, it's a TB and we really have no where to test it other than track. Heavy load yeah, scared the **** outta me when I tried it on track.

No, didn't think about that. Back to the manual!
 
im guessing there is also some kind of MAP sensor on the throttle bodies somewhere that runs the A/F map for the ecu. That could be checked to. OR it could be some wire in the harness that happens to vibrate loose at that rpm?....then you're SOL :p
 
Friend had a kill switch cause an issue around the same RPM. Would just cut out then mysteriously come back to life as the RPM dropped.. Ended up being poor contacts. Replaced the switch and all was well
 
Thanks guys for these suggestions, I guess I'm not done troubleshooting.

Back to the garage as soon as I can get his bike up to mine. Sigh
 
bump**** just out of curiosity.... Did you figure out the problem?
 
Nope, not yet. He ended up switching groups for Mosport and I let him use my bike for the days. Cam and crank sensors perhaps?

Not the TPS, that was one of the first things we checked.

BTW, I'm gonna check the kill switch too. Couple of people said this last week, maybe, just maybe it is this easy!
 
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How do you check a TPS? They are sealed units. Suzuki and Yamaha had issues where the bike would act weird with rpm and even cut off.
They checked the voltage but all that meant it was 'working'.
TLDR - The TPS will pass the ECU check on startup BUT then the ECU stops checking and the TPS is out of whack. I forgot the exact details but the TPS was outside of the ECU path so when it freaked out the bike thinks it has no gas or too much gas and kills the engine as a safety precaution.

Unless you swap out each sensor then I don't think you can be certain.
Hopefully it's as simple as the kill switch.
 
So swapping out a working TPS (mine) and installing it at the same position wouldn't tell you yes or no.

No, not sealed, at least not on our TBs.

We moved his TPS around, still cut out. Replaced it with mine, still cut out.
 
How do you check a TPS? They are sealed units.

Oscilloscope on the signal wire, checking for dropouts at various throttle positions

Edit: Method used by @meme works to
 
So swapping out a working TPS (mine) and installing it at the same position wouldn't tell you yes or no.

No, not sealed, at least not on our TBs.

We moved his TPS around, still cut out. Replaced it with mine, still cut out.


great, onto something else
that is certainly one odd issue
did you swap wiring harness?
 
FOR ****S SAKES.

Kick stand sensor. It's always been a trackbike so it was jumpered out. Eventually wiring will degrade and the circuit won't complete.

Bike runs well!
 
FOR ****S SAKES.

Kick stand sensor. It's always been a trackbike so it was jumpered out. Eventually wiring will degrade and the circuit won't complete.

Bike runs well!

perseverance and mechanics go well together....well done and thx for sharing

soldered now?

lmao "FOR ****S SAKES."
 
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