sheared a flywheel key on 1972 Johnson 40 hp. Is there anything special you have to do with the timing or top dead center when reinstalling the flywheel and key?
THe flywheel key is what takes care of the timing, so nothing special needs to be done with TDC or otherwise. Clean your crank taper of all all grease and oil, install the key and flywheel, and most importantly----torque it to specs. If you don't use an OEM key and don't torque it properly, it will reshear and eventually ruin the crank.
JBJ
No, but the flywheel bore and crank end must be clean and dry, plus the nut MUST be torqued to the correct value. You only get a few tries, before the flywheel and crank become junk. The reason for shearing is almost always the nut wasn't torqued. BTW, don't use a hardware store key.
Dankeeton, you should start your own post so that you don't get lost mixed in with someone elses.
I think the part number for your crankshaft key is 302602, check with your local dealer, they might have them in stock. Or you can order on-line, but the freight will far exceed the price of the part.
