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Mend Briggs & Stratton 28N707 Flywheel Lawn Mower Engine

keep shearing flywheel keyway?

BRIGGS & STRATTION MODEL 28N707 TYPE 0173-01
CODE 961022ZE first had a problem with fuel soleniod not shuting off flooding engine with fuel. installed fuel shut off (manual shut off )drained engine crankcase and cyl. replaced oil. When that happend tore off teeth on flywheel ringear replaced ringear with alum one (b/s replacement) Will the diff. between new one (alum.)and old one (plastic) give me problems with shearing flywheel keys.motor is free to turn by hand

BUTCHW
November 2010

Briggs & Stratton Briggs & Stratton 28N707 Garden Tools, Lawn Mowers Flywheel Lawn Mower Engine

easy solution
Take off the fly wheel and key,and put some fine grinding paste in between them and work as if you are grinding in valves (but in a circular motion complete turns to enable the shaft and flywheel to grind itself into a perfect fit,clean and check until good fit re-assemble and lock tight.

cg
December 2010

Check that there is no difference in the position of the keyway with respect to the position of the magnet, between the 2 flywheels. If there is, that's your problem (now), but that doesn't explain why you had the ring gear problem in the first place.

Ensure that the flywheel nut is TIGHT (to B&S spec.). The key is only a locator - it isn't supposed to cope with crank torque. The taper should be sufficiently tight to prevent flywheel slippage. I have successfully assembled and run engines with NO KEY at all to demonstrate this to dis-believing students!

phil_saunders(a)bigfoot.com

Phil Saunders
November 2010