1973 18 hp evinrude flywheel key shearing

[HighTrim]

Re: 1973 18 hp evinrude flywheel key shearing

If the Key is just to position the flywheel and the proper torque keeps the flywheel in place why is the OMC key
supposed to be the key(no pun intended)to success.

Ive always assumed, maybe incorrectly, that the hardware store keys are sized/shaped wrong to fit the specific contours/angles of the OMC flywheels,crank.

Cant say for sure, as I have never bought hardware store keys to compare them. I have repaired many a sheared key for a fellow boater that tried the aftermarket key though.

 

[kbait]

Re: 1973 18 hp evinrude flywheel key shearing

If the Key is just to position the flywheel and the proper torque keeps the flywheel in place why is the OMC key
supposed to be the key(no pun intended)to success.

I've never tried a hardware store key, but I assume the hdwr version doesn't allow the flywheel to mate properly to the shaft taper, even after torque. So, flywheel isn't bonded to shaft correctly and shears the key. Like it would shear an omc key if not torqued correctly. My .02 anyway..

 

[Tim Frank]

Re: 1973 18 hp evinrude flywheel key shearing

Woodruff keys conform to an ANSI standard...or at least they are supposed to.
It is more likely a quality of steel issue/hardness issue.