DF40 Hit rock will not start

[searay_43]

"I hit a rock and broke a prop

"I hit a rock and broke a prop blade, now the motor will not start. Is it possible that the flywheel key sheared causing the timing to be off?"

 

[superpole727]

Either that or you twisted the

Either that or you twisted the crank.

 

[searay_43]

Thanks Robert does the key pla

Thanks Robert does the key play a part in timimg? The engine turns over fine and the drive gear appears to be functing from the point thst the prop free wheels in nuetral and is engaged when I shift into forward. How common is it for the key to shear?

 

[blackbetty]

"I'm not a mechanic, but s

"I'm not a mechanic, but shearing the key would certainly mess up timing. Are you getting spark at the plugs? If so, the timing is probably off. I would think if it was a crank issue you would hear or feel it while attempting to turn it over.
Check for spark, if its there, check the key."

 

[superpole727]

I guess my post did not go thr

I guess my post did not go through this morning.

Blackbetty is correct about the keyway. But the DF40 uses a press fit crankshaft timing gear on the bottom. You can twist the gear on the bottom of the crank from impact. It throws the timing way off. I have seen this a few times. Exactly the same complaint hit rock broke blade no start. Chk your compression.

You can spot weld the the gear on the old crankshaft and re-time it but the factory marks will no longer be correct. You will need good a tech for this job

The best thing to do is replace with new crank and spot weld the gear so it don't slip next time that happens. You might want to call your insurance company.