crankshaft key

I have a 76' johnson 25. I keep breaking the crankshaft key. I have not had the motor to long and have rebuilt the points, condensors, waterpump etc. Motor has good conpression and ran great for a while. Then I broke a crankshaft key so I purchased another one and I broke that one before I could get it started. The second crankshaft key was very light compared to the first one, (almost like aluminum). What are these keys supposed to be made of? Can I use a key that I can get at tractor supply or does it have to be a "OMC" part? and what could be braking all these keys?

you need to find a keyway made from steel. aluminum is to soft.

moose

buy the OMC Johnson/Evinrude key.

The flywheel key must be aligned so the the flat outer surface is aligned straight up and down, not aligned with the crankshaft taper.

Then torque the flywheel to exactly 105 foot pounds, less results in a sheared key.

Thank you Macgyver, That figures out what I did wrong. I only tightened it as hard as I could holding the flywheel by hand #-o . Atleast the keys are cheap. Live and Learn