A friend called and asked me to look at his lawn tractor engine, an OHV Briggs, around 12 h.p., so i went.
He said he couldn't keep the flywheel key from shearing. I looked at it, and sure enough the key was sheared. He said he used 3 keys, and each one sheared right away! The flywheel nut didn't have any kind of locking washer under it, and he said it didn't need one! I even tightened the nut, using his hand operated, 1/2 in. drive torque wrench, but as soon as it starts, right away the key shears. I think he is wrong about the locking washer, but i said i'd ask here.
The engine turns easily with the starter. And it even ran a bit, but without the locking washer, it sheared the key. When it started, the engine sounded ok-no rattles, or thumps. Also, this machine looks like it has sat outside, uncovered, for most of its life! Never blown off, or squirted, or any maintenance. The machine came as a gift, and my friend wants to get it going. The P.O. said he installed a new battery in it, yes--around 5 years or more, ago. A sad looking piece, it is. And, yes, i know about squirting them off with the garden hose---but this is an extreme case of dirt! Any help welcome.