Key Keep Sheering

[jucks]

I Have a 1971 . 20Hp evenrude.that the flywheel key keep sheering. What could be the cause for that?

 

[racerone]

The key puts the flywheel in the right place , it does NOT drive the flywheel.--------A properly fitting set of tapers is what is needed.-------------So use some valve grinding compound and lap the tapers together. This will give the proper fit.-------You must use a factory key , hardware store keys may not be the same.

 

[Boobie]

And don't forget to torque the nut to the proper spec with a torque wrench, not an impact driver.

 

[jucks]

Thanks very much.I will do that.

 

[bill_w]

Check the point gap or better yet, use a timing light to check timing. If too far advanced, or if the points open too much, that will shear the flywheel key too.