[orionengnr]

Okay, I bought another project bike yesterday (Monster 1000 DS S2R).
The owner said "the motor just quit" while on the highway and it won't re-start. He said that it did not seem to have compression. I figured a belt let go, as it has 16000 miles and no service history (3rd owner).

But...with the belt covers off, the belts are still attached. Turn the crank, and the pistons are moving, but the cam layshaft (for lack of a better word) is not. From looking at the diagram, it appears that the layshaft is driven off of the left end of the crank by a pair of gears. I suspect that the one on the layshaft may have had the nut back off, or the Woodruff key has sheared/disintegrated.

Has anyone heard of this? Is there actually room for the gear to become disengaged from its mate without grinding the hell out of something?

Looks like I need to pull the left engine cover, and if I recall correctly that is not a simple as it might be. Will I need to pull the flywheel as well?

And finally, I am assuming that I will find that some pistons and valves have made a rude acquaintance.

I have LT's book and have read it once (several months ago) but don't remember anything about this. I will dig back into that as well.

Thank you,as always. This board is a great resource of kowledgable and helpful people.

 

[Tuned]

So you turn the engine over and the lay shaft doesn't turn at all? EEK!!!!

I would start by pulling the belts off and seeing if the cam's turn. If they do, then you maybe in luck.

If they do, then perhaps the gear on the left side which drives the shaft, simply fell off. It can happen…

 

[orionengnr]

So you turn the engine over and the lay shaft doesn't turn at all? EEK!!!!

Exactly. Sure wasn't what I was expecting when I went to look at the bike. To be honest, I did not know how/where the drive for that shaft actually was (obviously, off the crank, but I would have expected it to be taken off the RH side.)

So, I made the decision and bought it. And now I will learn something new.

BTW, any more input on removing the LH side cover, and will flywheel removal be necessary?

Thanks again.

 

[Tuned]

It's that big gear in the top left hand corner of this image, same shaft that drives the water pump. Because it's part of the timing system it's locked in place pretty well. Notice in this picture, the nut that holds it in place is missing!!! EEK!

It drives from a gear located behind the starter gear. But if that nut's missing, the gear could theoretically back off and get dislodged. YEAY!

 

[orionengnr]

Belated update

Sorry, haven't been on the board for a while, and forgot about this thread.

Bought the bike, started disassembling sometime thereafter. Didn't take long to determine the issue--pulled the LH engine cover (alternator cover) and the flywheel nut fell out.

Flywheel had moved outboard a little--doesn't take much.

The idler gear behind the flywheel disengaged from the cam drive shaft...cam stopped turning. Rear wheel kept the crankshaft turning for a while, with predictable results.

Prior owner claimed to have never had the flywheel removed, but who knows? He also never noted the source of an oil leak that was pretty prominent and pretty apparent.

Got it running, and someone made me an offer I couldn't refuse, so it has a new home.

Next project...inbound, maybe this weekend.

Thanks again to all, and hope this helps the next guy who has this problem.