Losing power at high rpms

[MistahT]

Sounds to me like your throttle bodies are slightly out of sync. Does it rev fine? Does it stumble at all, or die when the throttle is snapped, then quickly released?

The bike runs like a fine clock 99% of the time. On throttle, off throttle, up and down the range, revving in neutral... the bike acts like it always has.

The only stumbling/stalling I've had is immediately after it cuts power in the upper rev range.

 

[taylorisking21]

I think you've got it figured out then, sounds like some bad gas.

Hopefully the fuel system cleaner does the trick!

 

[leem00]

The bike runs like a fine clock 99% of the time. On throttle, off throttle, up and down the range, revving in neutral... the bike acts like it always has.

The only stumbling/stalling I've had is immediately after it cuts power in the upper rev range.

I am wondering if it is a loose or chaffed wire to the pcv?

 

[iaminsider]

That does not sound like bad gas to me. I hate to say it but it sounds like the issue lies with the PCV. Either wiring harness has some issues or the controller itself.

 

[98Deathmage]

The bike runs like a fine clock 99% of the time. On throttle, off throttle, up and down the range, revving in neutral... the bike acts like it always has.

The only stumbling/stalling I've had is immediately after it cuts power in the upper rev range.

Sounds to me like an electrical issue. Would definitely recommend unhooking the PC and seeing what happens. Also, do you still have your GoPro? Maybe mount it to your tank and watch your dash and record what happens so we can see an example of whats happening?

Also, I am around after 545p on Monday so I could swing by and see whats up?

 

[MistahT]

I should have a chance to get into the bike tomorrow and unhook the PCV. I've got a new helmet and no gopro mounts, but I'll try to find my suction cup one to record what happens. I'll let you know if I need a hand but I think I've got it.

We need to do some group riding in MD btw. Seriously need it!

 

[MistahT]

So ****ing pissed and fed up with this thing.........

Unhooked the pcv and went for a ride. Speedo doesn't work, reads 0 the whole time. The bike was having issues even passing 8 or 9k. Got home, ripped it apart again, I had knocked 2 hoses off the airbox. Took it for a quick neighborhood spin, didn't get to redline, seems better but speedo still doesn't work.

 

[Scott_Thomas]

So ****ing pissed and fed up with this thing.........

Unhooked the pcv and went for a ride. Speedo doesn't work, reads 0 the whole time. The bike was having issues even passing 8 or 9k. Got home, ripped it apart again, I had knocked 2 hoses off the airbox. Took it for a quick neighborhood spin, didn't get to redline, seems better but speedo still doesn't work.

Think maybe you f'd something up while doing the naked mod? Blown fuse for instrument cluster maybe? Sorry you're having so many issues Bro, weather is just now getting beautiful. Hope you get it fixed. Hang in there.

 

[MistahT]

Everything in the instrument cluster works except the speedo and the trip odometer. It worked perfectly last time I rode it before removing the pcv, but I'll check fuses when I get some time next.

 

[Scott_Thomas]

Everything in the instrument cluster works except the speedo and the trip odometer. It worked perfectly last time I rode it before removing the pcv, but I'll check fuses when I get some time next.

Definitely sucks, did you plug harness back together after removing pc5?

 

[MistahT]

Definitely sucks, did you plug harness back together after removing pc5?

Oh yeah, definitely. If left the power, ground, and speed sensor hooked up to the pcv, but I unhooked and reconnected the 4 factory plugs.

 

[Scott_Thomas]

Oh yeah, definitely. If left the power, ground, and speed sensor hooked up to the pcv, but I unhooked and reconnected the 4 factory plugs.

Okay was worth a shot. Wonder if your wiring got chewed by some little critter.

 

[MistahT]

Okay was worth a shot. Wonder if your wiring got chewed by some little critter.

Nope, I reinstalled my harness just last week and my garage is critter free (with the exception of spiders, man I hate those things! Had them wake up in my helmet and boots on rides, not fun)

 

[Scott_Thomas]

Well on a turn of event my bike completely died on me on the way home from work. Was fine in 2 hours of stop and go traffic because of an accident. Died not long after I got going again. I'm thinking mine has to do with new gas cap. When I went to open gas cap it was under tons of pressure. Now waiting on daughter to bring my truck and brother in laws trailer. FML, first time riding to work all year.

 

[blkbrd]

My 2 cents...

Just a thought. The PCV is hooked up to the speed sensor wire. Which method did you use to do this? Cut and splice, some type of connector, remove section of insulation and solder? Is it possible the speed sensor wire now has a break in it at that connection?

Losing power at high RPM...I would blame voltage first. Check stator and rectifier. If they test OK check coils, also check the condition of the wires that supply +12V to the coils. I'm guessing the ignition system cant supply enough voltage consistently at that high RPM.

 

[alaskanflyboy]

Losing power at high RPM...I would blame voltage first. Check stator and rectifier. If they test OK check coils, also check the condition of the wires that supply +12V to the coils. I'm guessing the ignition system cant supply enough voltage consistently at that high RPM.

If it could be voltage related, would the battery be worth looking at? I'm not familiar with our bike's electrical system. However, I know in most modern cars the battery and alternator work in parallel, with the battery supplying a stable voltage for computer components.

 

[blkbrd]

If it could be voltage related, would the battery be worth looking at? I'm not familiar with our bike's electrical system. However, I know in most modern cars the battery and alternator work in parallel, with the battery supplying a stable voltage for computer components.

Definitely worth getting battery load tested. Most shops should do this for free. They do in my parts at least.

 

[MistahT]

Haven't had any time but will be checking the fuse box, my battery's readout and speed sensor wire tomorrow. Thanks for sticking with me through this fellas, it's driving me crazy!

 

[mike]

Haven't had any time but will be checking the fuse box, my battery's readout and speed sensor wire tomorrow. Thanks for sticking with me through this fellas, it's driving me crazy!

Just curious have you tried to pull the fault codes from the dash? Just because the check engine light is not on doesn't mean there aren't stored faults. I have been a mechanic for going on 13 years and running fine at low rpm and losing power in high rpms kinda sounds like it may be starving for fuel. If it had low battery voltage to the injection system i doubt the fuel pump would even come on and if it did it should definitely set a fault.

 

[MistahT]

Just curious have you tried to pull the fault codes from the dash? Just because the check engine light is not on doesn't mean there aren't stored faults. I have been a mechanic for going on 13 years and running fine at low rpm and losing power in high rpms kinda sounds like it may be starving for fuel. If it had low battery voltage to the injection system i doubt the fuel pump would even come on and if it did it should definitely set a fault.

How do I pull fault codes?