Broken Timing chain?
 

So the bike won't start. ('89 3AJ Tenere) This wasn't too much of a worry until I scared myself with a huge backfire when cranking it over. Then, thinking back to how the starter motor didn't seem to be having to work as hard as normal, I have come to the conclusion that the timing chain has snapped. It's either that or there's a valve stuck upon, right?

So, while I ponder whether I'm going to brave the bottom end and do it myself, a couple of questions for the assembled knowledge:

Is the XT600 engine an interference engine, and if so will being cranked a load of times with a snapped chain have damaged the piston/valves?

Are there any other jobs I'd be as well doing while I do the timing chain?

Cheers.

Oeps
 

Yes it is. Interference engine.

Easiest way to verify; open valve covers and check:
A - When the engine is very carefully cranked by hand, are the rockers and valves moving?
B - Does any of the valve(s) have (very) excessive play?

If A - timing chain OK, if not A - chain broken
If B - valve(s) stuck open

Bottom end does not need to be opened to replace the timing chain - only remove LH cover and rotor. Bottom end of the chain lives there. And of course the top end needs to come off.

Auke

I just had my engine serviced because the cam chain also broke while i was at 50mph... both my 2 intake valves were bent....luckily nothing else got damaged because of that..

One thing...do not forget to align the timing points if the chain did brake. It is crucial or you might end up having to reopen the engine once more.

If I were you I'd had the bottom end checked for any other possible damage it might have happened (as I did).

I only went for the mechanic because he's a friend (yes, it's a small island) because he has a little more knowledge than me AND has all the tools needed..


Later!

Vando :cool4: