This is driving me crazy. After my bike warms up I loose all power to the back wheel. The power plant is stable, but I had to rev it up to 7,000rpm's in first gear just to inch it into the garage. I thought it was the clutch plates so I just replaced the friction plates, steel plates and springs but the problem persists. It feels like once the bike is warmed up there is some back-pressure keeping the clutch engaged (lever pulled in) when it is not. Like I said this only happens when the bike is warmed up. Any thoughts?

 

My first thought was the clutch as well , but as it's all been renewed.....? Maybe the hydraulics need bleeding???

 

?????

hows your oil level ? - too high ?

 

Could it be the clutch actuator rod is stuck somehow ? It fits behind the clutch unit (which has the speedo drive in it too) - as I recall the movement isn't very much, and if the pressure's down somehow.......................
I've not had mine apart, but remember a friend had a similar problem with an early model.......

 

The cluch is very tight. Previously, after sitting in the garage all winter, the clutch went slack so I had a friend come out and bleed the cluch which resulted in the tight clutch. I will have him out to see abut bleeding it again and gain some play at the lever. Does anyone know why this would only be a problem after the bike warms up?

 

Have you replaced the clutch fluid? Brake & clutchfluid attracts water, and that water may boil/vaporize at the slave cylinder when the engine gets hot. Just a theory...

 

When most metals heat up they expand. If the clutch is tight when cold then as the actuator lever heats up it will get longer forcing the clutch plates apart. Sounds like free play may be the problem. Too much free play however will mean that you find it hard to change gears because the clutch plates are dragging.

 

I always favor trying the easiest fix first. Is there too much fluid in your clutch master cylinder. There is a line in the master cylinder that indicates the proper fill level. If you go past this line, it might result in too little free play (I've only had the opposite problem- too little fluid resulting in too much free play making shifting difficult). Open your master cylinder and check the level and spoon out any excess fluid if it's too high.

 

Too little fluid in the reservoir will cause the clutch to suck air into the line when pulled in.
I've not found too much fluid to be a problem, except in extreme cases when you refit the rubber insert and it spills all over the bike !
I'd suggest a complete draining and replacement of the fluid (the darker it is, the more water it contains) with dot 4 or better (never use cheap fluid)as has been said, water could be boiling in the line, causing pressure on the actuator rod, and clutch slip.
Let's hope it's that simple............
If it only happens when the bike's hot, what else could it be ?