Need advice: Kohler sv840 no start

[LawnWizard]

Just completed a longblock swap. Have everything back together. Engine started with a shot of starting fluid. Ran perfectly, smooth idle, smooth at 50% (didn't try to run at wot yet). Shut it down and restarted several times perfectly. Let it set about an hour now will not start. Replaced carb, same result.Turns good, good spark on both cyls starting fluid does not help. Good compression when turning by hand. Tried the choke in several positions, no difference. With spark, fuel and compression, shouldn't it at least fire and try to start? Puzzled. Any suggestions are greatly appreciated!

 

[Rivets]

First thing I would check is a sheared flywheel key. Wouldn’t be the first time I’ve seen where the flywheel wasn’t torqued properly and the key sheared on shutdown.

 

[LawnWizard]

Believe it or not, I just thought of that too! I had that happen on a Hustler Super Z with a Kaw 850. I've been so caught up in double and triple checking my work that i completely forgot about that. THANKS! I'll check and report back.

 

[LawnWizard]

BINGO! We have a winner!

 

[LawnWizard]

Thanks Rivets! I kept thinking that it acted like it was out of proper timing. I was not inside the block so I just kept going back over my work. It dawned on me when I was in the shower that if the flywheel had moved (like my Super Z did), the timing would be off.
I very much appreciate your help!
Hugh

 

[Rivets]

Glad to hear it.