General 650 rebuild problems

[jmb79]

I am in the process of re-building my 650cc engine. The old timing chain was quite slack and has no tensioners. It was pointed out by Toshi that it is probably off a 126 Bis. So I bought a new one with sprockets and tried to fit it last night. However there does not seem to be enough slack in the chain to get it on. I have tried envy thing I can think of but once the chain is on both sprockets I can quite get the camshaft sprocket onto the end of the camshaft. It needs a few mm of slack. Any suggestions? The old one goes back on fine and the slack that was there before striping appears to have gone, so I could always use that I suppose.

In addition, since replacing the main bearings and re-fitting the crankshaft, there is a few mm of play (i.e. horizontal movement in the crankshaft). I can't remember if that was there before I striped it down. Is that normal?

Jamie

 

[Franko500]

Sounds like you need to try another chain as it should fit - you cant really go wrong with it.

what do you mean by horizontal play?
Do you mean you can push the crankshaft in and out of the block? if you havent fitted the front crankshaft pulley & bolt then yes you will be able to do this.

 

[jmb79]

Cheers Sean, having just got to the stage where the front crank shaft pulley and bolt are now fitted I realise that I was panicking unnecessarily!

After persevering with the chain and hanging some weight off it when fitting it I finally managed to get it on but it was an absolute pain.