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Hank F.
Hank F., Technician
Category: Small Engine
Satisfied Customers: 15268
Experience:  Certified on Onan and Generac generators
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how do i time an onan p218 g engine i took the fly wheel off

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how do i time an onan p218 g engine i took the fly wheel off to to replace a sheared key and also took off the trigger ring and dont know how to put it all back together to fire right and fire at all


The trigger ring simply snaps onto the crankshaft. Just align the tab on the trigger ring with the recess in the base of the crank.


Insert the key into the slot of the crank, and carefully place the flywheel back on, aligning the slot in the flywheel with the key.

The key is what sets the timing.



Customer: replied 7 years ago.
ok ive done that and it still will only backfire it wont even try to start.I sheared the key two days ago on it when it was running. i had a wire running from the positive post of the battery to the positive post of the coil because thats the only way i could get this engine to fire. i pulled this particular wire off while it was running and it slipped out of my hands and back onto the positive post on the battery that caused the engine to backfire hard and shear the shaft key now i cant get it to do anything but get it to backfire

Is it actually backfiring (through the carb), or after firing (out the exhaust)?


When was the last time you installed new spark plugs and adjusted the valves?


Customer: replied 7 years ago.
just got it so i put in new plugs never adjusted the valves but i did have it runnng like a top before that hot wire to the coil touched after it was already shutting down

It is a long shot, but if it backfired that hard, it is possible that it spun the gear on either the crankshaft or camshaft.

The engine would need to be disassembled to verify this.

If you want to dig that deep, I can upload a manual for you.



Customer: replied 7 years ago.
that would be great i cant find one anywhere in MO it did back fire hard enough demolish the shear key and deafen me i think a manual would be great.

No problem.


Click here to download.


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