Key under flywheel keeps shearing off.

[Bearcamp]

I have a 15 hp Montgomery Wards that keeps shearing off the woodruff key. I install a new one , start it up and goes to high rev, stalls and won't start again. Sheared key. Is it because it's starting on high speed or what. These are a pain to install. You have to tap it down behind the cam for the points and I already ruined 2. Is there an easier way?

 

[JB]

Re: Key under flywheel keeps shearing off.

Tell us more about your engine, BC.<br /><br />Under what conditions is it running away? Do you have it in water or on muffs?<br /><br />Fix the reason for the runaway first.<br /><br />Shearing flywheel keys is something that happens when the flywheel or crank is damaged or the flywheel is improperly installed.<br /><br />Let us know.

 

[Bearcamp]

Re: Key under flywheel keeps shearing off.

It really doesn't have a way of keeping the throttle down when not in gear like the newer ones. And when I start it, throttle is usually close to full throttle. So it revs up pretty high. I have it in a barrel of water and don;t have the tiller handle on it cause it's getting repaired. So basically I might have the throttle too high, is that correct?

 

[alcan]

Re: Key under flywheel keeps shearing off.

Hey Bearcamp<br />Several different manufactures made outboards for Montgomery Ward. Maybe you could post the model# of this ole honey dripper so we can tell what yer talkin about.

 

[HarryHydro]

Re: Key under flywheel keeps shearing off.

Hi Bearcamp!<br /> Could it be the engine is liquid-locking a cylinder? I wouldn't think just an open throttle from start would have enough torque to tear a key. While running, I think the only torque drag on the flywheel would be the charging system, and that's almost nothing. Maybe something binding in the lower unit, too. Keep us informed what you find. Sounds interesting.<br />Harry

 

[jasper2447]

Re: Key under flywheel keeps shearing off.

This happened to me with a 55 Chrysler and it turned out to be the flywheel not seating adequately on the taper - after the first time there was damage to the tapered shaft and to the inside of the flywheel - i had to get both re-ground to a smooth fit.<br />The other thing to check is that you are applying enough torque to the large bolt on top of the flywheel when refitting it - this torque setting is usually very large and difficult to achieve, I recall. Being a little slack was allowing the flywheel to move on the shaft and - bingo - the key shears.<br /><br />John B

 

[scotiany]

Re: Key under flywheel keeps shearing off.

Jasper is on the right track as far as cleaning the flywheel-shaft. Get some valve lapping compound-not valve grinding compound. Apply a light coat to shaft. put flywheel on lightly. Rotate 1/4 turn back and forth about 10-15 times. Lift wheel and turn 1/4 clockwise. Repeat proceedure. Do this until you've rotated flywheel all 4 times. BTW, you can clean and replace compound between wheel rotations. Repeat until the inside taper of the flwheel and the shaft are smooth.