Topic: 82 650sc cam sprocket

[kidcaesar]

Hi everybody -
I am new here - I am trying to resolve what I believe is a cam chain/tensioner issue.  I have the valve cover and rocker arm assembly off; also I removed the two bolts on the cam sprocket. I've done this before on my 77 750f. But there is absolutely no slack in the chain. I can't get the chain off the sprocket nor can I get the sprocket back on cam. The engine rotates fully, no kinks in the chain, no sign of wear on the chain. I have loosened and tightened the tensioner bolts with no affect on the tension of the chain.
Thank you.

[scunny]

my 650 (with new chain) needs a bit of leverage to get in position. once there, everything is good. well has been for the last 7 or so years.

[DaveBarbier]

What I’ve done is take a long flat blade screw driver and use it to push the tensioner away from the chain. First loosen the tensioner nut, then press the tensioner away and then tighten the nut. That should give you more slack. But they are tight. If your sprocket has the chain on it and is off the cam area where it normally rides and the chain still won’t come off the sprocket there’s something not right. The chain should be somewhat loose if the sprocket isn’t yet on the cam.

[DaveBarbier]

I admit I’ve used a big flat blade screw driver and help “pry” the sprocket into the cam. It only needed to be lifted about 1mm or less. It was so close but I couldn’t do it by hand. I’ve done this with my 550 and 650 both with new chains.