[1rusty1]

I had the same exact issue just two months ago. Worked great when cold but once warmed up the clutch would start to slip and then eventually I would have to push it. The fix seemed too easy to believe but it worked. The master cylinder resting on my handle bar had a small relief plug/port that was clogged.
To test:
1) Remove the cap/top of the master cylinder. 2) Remove the small silver cap resting at the bottom of the cylinder. 3) Pull the clutch lever. 4) You should have clutch fluid/dot3 shot a stream out of the cylinder about 6 inches to a foot. 5) If nothing comes out, your relief hole is plugged. 6) You will see one larger hole and next to it a hole so small you may not see it. Insert a bobi pin (very thin pin/or wire) into the small hole to loosen the clog. 7) Pull the clutch again. If fluid now shoots out, the problem should be fixed.
2) If this is not the problem you may need to change and bleed the fluid (make sure you bleed the banjo bolts at the master and slave as air stuck in these areas can cause issues)
3) If changing fluid does not help, move to rebuilding the master and slave cylinders.
Hope you have it running soon.

+1 on the motor oil as well

 

[1rusty1]

kjemm32:
Glad to hear it's working for you. It's a great feeling to be able to go for a long ride and not have to worry about the clutch slipping. Believe it or not, when I was talking to a honda dealership about the problem he said his old bike had the same problem and he was never able to find the fix.


slfronza:

The bike does not need to be running to push fluid through the relief hole. Just make sure you are cleaning the correct hole and keep at it as you may have more gunk plugging it up then I had. You might need to try what kjemm32 did to unplugg his. One question: do you have any leaking around your slave cylinder?