Power loss to wheels but engine revs strong.

[mfrias2nd]

Guys, tips please... about 35k miles maybe more. Just yesterday I was riding when I was cruising in 3rd and hit the throttle and the engine revved but hesitated in pushing me forward. Today I noticed it more and more. This has never been a problem before so it's nothing that is currently configured on the bike. So what do you guys think? Air/Fuel ratio? Clutch? any ideas would be greatly appreciated as always!

[georgesgiralt]

Hello !
If the engine increase RPM, and "noting happens" then the clutch is slipping.
But why ?
At first try to set the play as per the book and see what gives. If still the same problem, opening the clutch to see is in the pipe...

[mfrias2nd]

I'll definitely check out the book on this topic. I wasn't aware I could adjust it. thanks...

[mfrias2nd]

Any other idea guys? need to know before i go buy a new clutch and schedule the work ie. time without my bike = (

[Barry]

Only the possibility that splines have stripped where the output shaft connects to the clutch plate. That would tend to go all at once though resulting in no drive at all.

[mfrias2nd]

Thank you... i've only noticed the slipping when i throttle hard mid gear. I usually baby it on take offs so i can't tell how it's been responding there but definitely noticing mid gear slipping. my tach will shoot up and i'll hardly speed up then slightly it accelerates. almost like a delayed response.

[georgesgiralt]

Have you tried to adjust the handlebar play as BMW specify ?
If yes and problem not solved, then, time to open up to see.

[nhmaf]

It is most likely the clutch slipping, though it might also be a problem with the transmission if the problem oonly/always happens in a particular gear.

The clutch slipping can be due to multiple factors, but all would entail having to pull the gearbox and taking apart the clutch assembly to examine the parts:
1. Could be worn out friction disk and/or pressure plate
2. Could be oil/grease contaminated pressure/friction disk (and if oil contaminated, then either rear main seal or oil pump cover seal leaks are most likely culprits)
3.  Possible worn out diaphragm spring in clutch assembly.


Are there any mechanical noises or vibrations that accompany this when it happens, and if so, from approximately where on the motorcycle does it seem to come from?

If the clutch splines were gone, you'd rapidly lose all motive power, and the thing would sound like a 50HP food processor chewing up an aluminum can r as soon as you'd try to put it in gear and go.

[tvrla]

First make sure you've got some play in the clutch cable. Does the lever move a little bit before pulling the cable?

The cable can be going bad and some broken strands don't allow the cable to completely relax. That would keep the throwout mechanism under strain and the clutch under reduced tension.

It's also possible the throw out bearing is hanging up in the bore in the transmission cover. That's a common problem. BMW started making one of the bits out of plastic and it swells... just enough to stick in the bore. Carefully sanding it down fixes the problem. A new one isn't the solution since it'll do the same eventually.

If it's none of those, it's the clutch. But until you determine it's definitely the clutch, don't allow it to slip, as that will glaze it and then it will definitely need to be either sanded or replaced.

[mfrias2nd]

thanks thanks and thanks! no it's not losing motion right away only when i throttle hard in any gear. and the more I think about it the more i feel like the entire bike got slightly slower vs. the RPM's I'm used to... when i first noticed it i was in 3rd about 4k RPM's i revved hard to TRY and keep up with my brother on an RZ350 and she just skipped rpms flew up to 5-6k and then i let off the throttle and throttled softly and she went up normal.

[flybot]

Like everyone has said, the most likely answer is the cable is too tight or the clutch is worn out. My bet is the clutch. You can check the cable in a few seconds. The clutch is a major job.