TS250 Knock revisited

[neomuzzi]

Back again. On one of my last posts I was looking for some thoughts on a concerning "clunk" or "knock" that comes from the crank case after I roll off the throttle.

After de-mothballing this 1974 TS250 in just a couple of hours and only needing to clean the carb, adjust the timing, and get a new petcock it has been a very low level of effort to be able to ride this bike on a 3 mile loop that I use for testing. That is the good part.

The issue that keeps me from going much faster than 25MPH and just a couple miles from home is this loud mechanical "knock" that happens 1 or 2 times when I roll off the throttle to shift. It seems like it is coming from the trans. I can almost feel it in the drivetrain. I pulled that small clutch cover off and there really isn't much under there... I'd hate to have to split the cases on this old bike, but it just doesn't feel safe. Like one of the forks in the trans is catching on something, or the clutch is somehow at fault.

Any other TS250 riders out there experience any oddness in the trans?

Lastly, the only other thing I could think it is is like a small backfire in the pipe right at the exhaust port. Any backfire issues with these bikes?

thanks.

MG

[Puffs]

Following a moderator choice that is IMO biased and flawed (someone posting aggressive personal attacks is rewarded, while my technical posts are removed), I have withdrawn from this forum.

[MichaelTorre]

Failed rubber in the Kush drive at the rear wheel.....
m