violent jerk

Just a thought, while I wait for my endoscope to turn up and for it to stop raining for a test ride..
I was looking through the manual and saw that the clutch basket has rubber dampers inside. Is it possible that could cause the problem? If so, is there a way to test if it is the issue?

fineline wrote:

Just a thought, while I wait for my endoscope to turn up and for it to stop raining for a test ride..
I was looking through the manual and saw that the clutch basket has rubber dampers inside. Is it possible that could cause the problem? If so, is there a way to test if it is the issue?

As the saying goes Never say Never. It's possible but in all the years hanging around on this site, I haven't heard of an issue with those particular dampers. They are rubber and they sit in the engine oil and they are 40 years old.

The only way you're going to find the problem is exploring through the driveline looking for the slack.
Easiest way to check the secondary drive HyVO chain is to drop the oil pan. You can probably see the primary chain at the same time but maybe not able to take a good measurement of the slack on it. One of the guys on the site also pulled the rocker cover off and managed to take a measurement of the primary chain from the top and he determined that he needed to pull the engine and replace the chains. I think it was MCBoney almost 6  years ago. He was scared about tackling the job but we convinced him to dive in head first and if we had to, we would pull him out and resuscitate him. He got er dun all by himself. I think he posted how he made the measurement from the top.
It's a good read   McBoney's rebuild

Thanks Kawboy!  I'll have a read through that thread. I remember finding lumps of rubber in my oil which turned out to be my cam chain idler wheel.  Maybe as these bikes age we might start to see more and more disintegrating rubber parts, if so It's typical it would have to start with me.  Then again I suppose I could replace those without a complete rebuild.