Hot bike = stuck clutch

[jkoerpel]

Has anyone else had this issue?  I just got back from a 70 mile ride down to Jersey and this happened a bunch of times.  Graceful when you begin to ride out of a toll booth and the bike suddenly jerks hard on you and makes this bad squealing sound.  

I read on snowbums site that it could be 2 likely things, and wanted to see if anyone else has had similar issues with 79 R65.  Could be either:
- My piston in the throwout bearing assembly is expanding too much and/or the throwout bearing bore tolerancing is off.  This would require measurement and possible lathing/sanding of the piston surface.

- Excessive end free play of the crankshaft.  He specifically mentions the 79's sometimes had this issue.  If this is it, fixing is out of my scope and I would have to take it into the shop.

Has anyone had/dealt with this?  The stickiness and resulting squeal when the clutch engages was always there (mostly in 2nd and 3rd) but very minimal.  Now today it began to happen in first pretty badly.  

Any help appreciated,
Josh

[Bob_Roller]

I think I'd start with checking the throwout bearing for issues .

I don't think excessive crankshaft end play would present itself and be a problem so quickly .

[tvrla]

Somewhere in my early wrenching experiences I acquired the attitude that it's most often the simple things. And it usually is!

So I start with the easy stuff and don't worry too much about it. The throw-out system controls the clutch, so inspect that first since that's the area of difficulty. It might just be a bad throw-out bearing.

I have had a transmission with a hogged out throw-out bore. The cover would have been junk if the machinist hadn't been able to bore it out and sleeve it with a brass bushing.

[Barry]

I've never had that problem with my 79.  The throw out piston is not too difficult to remove. I pull mine and give everything a good clean when I do a spline lube.  If it's stock you will have the type of pivot pin secured with an E type circlip which as discussed on a recent thread http://www.bmwr65.org/cgi-bin/yabb2/YaBB.pl?num=1339019640/4#4 is quite hard to spot. Look carefully between the support posts and the operating arm. Once the pins out you can withdraw the piston and radial needle roller bearing.