Power Loss at 10k

[RyanNicholson]

So unfortunately I had to sit out this past weekend after finding some serious issues with the bike on friday. The bike idles and runs great up until theres a load on the engine and it hits 10k or so...the power just plateaus and doesn't pull at all. This scares the crap out of me, since pretty much no matter what it is its over my head. The same thing happened to my friends Georges bike (one of Shane's old 07 600's) and the code it was sending back was a "Secondary Throttle Actuator Motor" or something like that. Al explained what it was and it makes a lot of sense but I'm not sure how to go about it. Something about hitting upper part of the tach it opens to allow more gas flow to the injectors or something. But I'm not sure if thats actually whats wrong with my bike, because my FI light isn't on.

As far as the bike goes, no engine work, no powercommander, slip on exhaust, basically bone stock. The engine is pretty tired.

I really dont feel too comfortable about trying to diagnose this on my own, any advice?

[13]

With no MIL lit up it's tough. Is there some sort of data link connector to hook up a scan tool? Any possible way to graph out engine sensor readings? Maybe an hour on a dyno would help? I deal with weirdo drivability problems fairly regularly, but not on bikes. I'll do some digging.

EDIT: Is there an EXUP valve on the bike? If it was stuck closed would it cause this problem? Would that trip an FI light?

[burnham]

I had a 2000 GSXR 750 with the "Secondary Throttle Actuator Motor" and the cables that drove it frayed and it stopped working. Ther was no code on the dash but it started running out of power around 10-11k. Suzuki changed it in '01 and got rid of the cables.
I have no clue as to how Yamaha does it. Maybe you could pull the airbox cover and load up the motor with the rear brake to see if the plates are opening?

[RyanNicholson]

i dont really have any way to get the sensor readings, but I'm sure theres a way to hook up a scan tool somehow. No EXUP valve on this gen R6 though.

I'm gunna tear it down tonight and get the airbox off to see what I find, like I said this is getting a bit over my head

[SSearchVT]

Check the simple stuff first. Throttle cables, vacuum lines, bad gas, plugged fuel filter, electrical connections (especially the ones in the kickstand and clutch lever). If it's a sensor or part of the FI system - theres a good chance it would throw a code or at least flash lights... Good luck.

[RyanNicholson]

so I stripped it down, removed the airbox, checked electrical lines and cables, and everthing "seems" to be fine....as far as my untrained eye can see.

anybody in the area that might know more about what I'm looking at that might be willing to come check it out?? Any help would be greatly appreciated and compensated.

[burnham]

Do you have a shop manual?

[RyanNicholson]

I do....its on my laptop in a pdf....i'm gunna do some more digging through it tonight.

[burnham]

I can come up one night this week and check things out with you. I have a meter we can check the resistance on your coils and sensors with, probably be able to rule some things out at least.

[Cerberus]

Check the simple stuff first. Throttle cables, vacuum lines, bad gas, plugged fuel filter, electrical connections (especially the ones in the kickstand and clutch lever). If it's a sensor or part of the FI system - theres a good chance it would throw a code or at least flash lights... Good luck.

good starting point here

my first thought was either exhaust restriction (would be caused by an exup valve not opening fully) (which btw would heat the snot out the exhaust valve.. ) or running out of sufficient fuel supply at top RPM, which is often due to a dirty filter or bad pump.. or even a bad fuel pressure regulator.

[RyanNicholson]

waiting for a call from someone here on the board thats just around the corner.... thanks for the offers/advice... I'll be in touch if it comes to it!