Clutch Issue, intermittent on warm bike...

[BLD]

I finally managed to get my '13 XC300 out on some real trails for a shakedown ride and had a blast. On my third ride, after several different trails, I stopped to decide which trail to take next and while in 1st, clutch lever in, the motor loaded up and the bike started to creep, and stalled. I fired it back up in nuetral and the clutch worked like normal. The clutch lever has a little play and clutch usually engages with the lever most of the way out. This happened a couple more times over the next several rides (prevented stalling by just going for it) and there were also times where I'd slow for a tight turn (clutch lever in in 1st) and would feel the clutch engage most of the way in... None of the problems seemed consistent and they would go away just as quick as they happened.

I'm using Motul 10/40 and the clutch works like a champ when cold or after sitting for days. No grabbing, stalling or squealing. After some searching I saw some posts mentioning bad seals or a scratch on the clutch master cylinder. Sounds likely, but are there any other things I should check? I'll tear apart the master cyclinder to check for issues and bleed the lines within the next week.

Thanks.

 

[Neil E.]

Sounds like you have leftover machining debris in the master cylinder.

 

[BLD]

Thanks Neil, I'll check for debris too. I took the cover off and all looks good, but I want to wait until I have more mineral oil before draining and dissasembling the master. Are there rebuild kits available for these ie. seals, retainers etc? If so, anyone have a preferred online vendor in the US they order from?

Edit: Search function is my friend... I have seen a couple posts mentioning the adjustment screw, if you adjust too far it can cause similar issues. I take it this is the adjustment screw attached to the clutch lever, that connects to the odd angled pivot point on the master (see attached image). I have fiddled with this a turn or two in each direction attempting to adjust the levers free-play and did not notice a difference in the lever. How do I adjust it so it engages the mc properly? Can you see the mc move through the small hole in the bottom of the reservour? The lighting was bad in my garage when I took the MC cover off, and I didn't want to mess with it until I have a syringe or vacum to bleed the line (see other pic).

Thanks!

 

[poelinca]

Re online vendor:

https://www.gasgaspartsguy.com/ if you are in the USA (i would contact them if they don't list the kit you need as the online shop is new and they might not have everything up yet)

http://www.motocrosscenter.com/ In Spain
https://www.greenlandmx.com/en/oemparts In Spain
http://www.enduropuro.it/ In Italy
There was another one in Deutschland witch I can't remember at the moment, and same for UK.

 

[Neil E.]

The adjuster on yours looks to be turned in a fair way; make sure there is some play before the master cyl plunger moves. I recall being able to see the plunger through the feed hole. I bought the repair kit through my local dealer; you should have no trouble getting one.

 

[BLD]

Thanks everyone for the help, this forum is awesome! I used the syringe and plastic tube method to bleed the line after the vacum kit I bought induced more air into the lines than it removed... I'm so glad to have found those threads and pics with the syringe trick! You should have seen the look on the girls face at the medical supply store, not only did they not carry syringes, but she looked at me like I was crazy when I asked for two syringes and some plastic tubing... Thankfully the local feed and farm supply knew exactly what I was looking for.

It turns out the adjuster had some involvement here too. I gave it a hair more slack when I bled the line, and now the friction zone is much larger and the clutch works like a champ. I took it out on some trails today and not only was the clutch easier to modulate, it was easier to find nuetral with my foot! There was no loading of the clutch so I think I'm off the hook rebuilding the MC for now, which is good since I want to spend that time and money on new fork seals and springs!