Flywheel Key

Just finished rebuilding carbs cleaned pistons and cyl, new points, condenser and coils. Reassembled everything and tried to start and sheared the key on the shaft that the fly wheel fits on. What did I do wrong and is this key easy to replace or do I need to tear it back down again. Manual is no help on this. I have a '72 Evinrude 25hp Model 25252

Re: Flywheel Key

the key is easy to replace, you have to remove the flywheel, when replaced torque to spec.

Re: Flywheel Key

If the crankshaft nut is not properly torqued down, your outboard will shear keys again and again. If it is properly torqued down, it won't happen.<br /><br />I don't have the torque specs for your outboard model, but you can find it in the service manual.

Re: Flywheel Key

Thanks for the encouragement, but How do I remove the upper bearing that holds the bottom part of key? Also the torque spec in the manual says 480-540 inch pounds, which translates to 40 to 45 ft. pounds witch I did. Does this sound correct?

Re: Flywheel Key

Do you have the magneto cam off? This is a little metal collar that goes over the crankshaft and activates the points. It pulls straight off.<br /><br />If it's jammed on by the sheared key, you may have to remove the magneto plate to pry it. That's fairly easy to do, just remove the linkage and 4 phillips screws. Then it will lift off and out of the way.<br /><br />40-45ft/lbs sounds correct. Verify your torque wrench is accurate, and clean the end of the crankshaft and the taper in the flyweel to remove any burrs, etc. Then lap the flywheel to the crankshaft employing vavle grinding (lapping) compound for a perfect fit. Then clean the taper & crankshaft up, leaving no trace of grease or oil.<br /><br />The key is never supposed to keep the flywheel from rotating - it's purpose is simply to index it for installation.

Re: Flywheel Key

you don't remove any bearing that I know of, just remove the flywheel, remove the broken key from the flywheel and shaft. as for the toque if thats whats in the manual then go for it. you can call your local dealer and get the specs.

Re: Flywheel Key

That's the problem I'm having removing the collar. It is jammed and I dont want to damage seals. Is a crowbar in order or is there a tool to remove it. did not want to destroy all work done. Should I replace the collar?

Re: Flywheel Key

Try to get it off without breaking it. You'll have to go to the wreckers for a replacement if you do. Shouldn't be that bad though - it's a pretty common part.<br />Normally it just lifts off. The broken key has it jammed. Get the mag plate out of your way and try grinding what's left of the key with a dremel (if you've got one). The tool of choice would be a 2-jaw puller if you could get it around the cam alright, and a bearing seperator if you don't. But right now you're in 'improvise' territory, especially if you don't have either of those tools handy.

Re: Flywheel Key

Two large screw drivers did the trick. Now Can't get the key out of the shaft. Seems to have become part of the shaft. I would like to pull it out in tact to take to the store to compare size and buy a new one. Is there a size number for these things or should I buy an assortment?<br />Thanks for all the help!!!!

Re: Flywheel Key

Good stuff!<br /><br />Get the correct key from the dealer. I haven't had much luck finding the 'right' key at the hardware store. PN 120395, and they'll probably have it in stock.<br /><br />Dig the old key out with whatever you have. A nailset and hammer seem to work well for me. Sometimes it takes some doing...

Re: Flywheel Key

Thanks for all the help. Finally beat it out and my wife (bless her heart) will pick one up a the marina since she is close. $3.00!!!