How to weld a flywheel on a 1976 Horse Johnson 55

Joesnowmobiles · May 6, 2002

Hi all, My flywheel keeps coming loose from the shaft because the key that holds the flywheel in place keeps breaking in the slot. Am I tightening the nut down to hard on the top? or should I have the flywheel welded. My timing is off because this keeps happening. What is the best way to remedy this? Thanks Joe

oldboat1 · May 6, 2002

Re: How to weld a flywheel on a 1976 Horse Johnson 55

had the same problem with a '61 Evinrude. Make sure the shaft is clean (no grease) and that the key is in correctly, then torque the nut down to specs. You probably are not getting the nut on tight enough -- sucker really needs to be tightened down (which is probably why flywheels can be so hard to pull). (Gee, welding seems a tad radical....)

Beernutz · May 6, 2002

Re: How to weld a flywheel on a 1976 Horse Johnson 55

After you weld it, throw it away. Before you do that, though, try a new key and some Loctite bearing mount.

Joesnowmobiles · May 6, 2002

Re: How to weld a flywheel on a 1976 Horse Johnson 55

Thanks I tightened the nut down as tight as possible but this is the third key that has busted, someone suggested welding on this board but do you think thats a bad idea? Its possible from the first three stripping out that I didnt put it in correctly? How do you put one in correctly do you insert it in the shaft before putting flywheel on or put in in after you put the flywheel on. If everything else fails should I weld?

Joesnowmobiles · May 6, 2002

Re: How to weld a flywheel on a 1976 Horse Johnson 55

Beernutz you mentioned loctite do I put that on the shaft?

clanton · May 6, 2002

Re: How to weld a flywheel on a 1976 Horse Johnson 55

Remove the key, lap the flywheel to crankshaft with automotive valve lapping compound, using a back and forth motion, you will be able to see the lap mark, when you have about 85/95 % contact, clean with brake kleen and rag, flywheel and crankshaft should be spotless, torque nut to 80-85 foot pounds, use OMC sealer on nut threads.

Joesnowmobiles · May 6, 2002

Re: How to weld a flywheel on a 1976 Horse Johnson 55

Thanks Clanton, but what do you mean by lap the flywheel to the shaft?

Franki · May 6, 2002

Re: How to weld a flywheel on a 1976 Horse Johnson 55

has the slot for the keyway been rounded at all by the previos problems? if so, that could very much agravate the issue. Also, I think what clanton means is to match the surfaces, valve compound is a gritty paste,, you put it between the two surfaces and move them against each other, it will hopefully remove material so that the surfaces mate properly.. but if the keyway is rounded.. then it may not be enough. Not sure I'd take to it with a weilder, the heat can do alot of damage, (warping) and if you actually need to get it off in future, do you plan to use an angle grinder??? regards Frank

G DANE · May 6, 2002

Re: How to weld a flywheel on a 1976 Horse Johnson 55

Be aware: There should be NO washer below the nut. I´ve seen a washer with too small hole used. The nut will ride on the washer, instead of the flywheel surface. It should be possible to make is sit there.

G DANE · May 6, 2002

Re: How to weld a flywheel on a 1976 Horse Johnson 55

I´d better finish my posts in the first time: The nut MUST be the original part, it has a turned edge to make sure the torque is on the flywheel, not the cranckaxelend.

clanton · May 6, 2002

Re: How to weld a flywheel on a 1976 Horse Johnson 55

You take valve lapping compoumd, place compound on crankshaft taper, set flywheel on crank, rotate flywheel back and forth by hand, keep conpound off of upper seal. Some of the new keys are a little larger. This is a 2 cylinder engine right?

Bob_VT · May 6, 2002

Re: How to weld a flywheel on a 1976 Horse Johnson 55

Just curious what are you using to tighten the nut? Minimum it should be a 1/2" drive breaker bar or even better yet...AIR tools. Forget using a regular wrench or 3/8" set. A few respectable impact blows should do it. Bob

Joesnowmobiles · May 6, 2002

Re: How to weld a flywheel on a 1976 Horse Johnson 55

Thanks guys for all the input, I will try to do exactly what you all suggested and yes to clanton it is the 2 cylinder model. And as to the question about what to use about what I am using to tighten the nut I was just using a regular wrench but I will be buying the correct socket so I can use the breaker bar. As far as the nut goes I need to have the turned end towards the flywheel is that correct? Thanks again guys

Joesnowmobiles · May 6, 2002

Re: How to weld a flywheel on a 1976 Horse Johnson 55

I know I am straying off the issue a bit but can someone tell me the correct amount of turns out on the idle screws on the carbs. Thanks Joe

Dhadley · May 6, 2002

Re: How to weld a flywheel on a 1976 Horse Johnson 55

Surface the bottom side of the nut. If it has small "galled" areas on it you may be getting contact only on those small areas. I've seen this before. Good luck!

Dhadley · May 6, 2002

Re: How to weld a flywheel on a 1976 Horse Johnson 55

Just thought of something else. Make sure you use the correct key and check the inside of the flywheel. If the inside is galled and/or out of shape you may be loosing the interference fit. Good luck!

Beernutz · May 6, 2002

Re: How to weld a flywheel on a 1976 Horse Johnson 55

Yeah, it goes between the shaft and flywheel. It was developed to accommodate for imperfect mating surfaces. And, like DH says, make sure you get the correct key. If it's not a really snug fit in the shaft and flywheel keyways, I doubt that anything will keep it tight. Pay close attention to the other suggestions from the guys here, too. Lapping her in is good, but if you're unfamiliar with the process, get help.

petryshyn · May 6, 2002

Re: How to weld a flywheel on a 1976 Horse Johnson 55

Joesnowmobiles I'd recommend following clantons advice to the letter. Resurface the nut as Dhadley states as well. Before you lap the surfaces, carefully file off any galling on the crank that occured from the previous failures. Polish the crank taper with fine emery cloth, then procede with course lap compound then fine lap compound. Nothing will restore a damaged taper, so I'd clean the flywheel and crank with lacquer thinner, carb clean or brake clean, wipe dry, then apply red loctite and torque to spec. Be sure to use a torque wrench. Guessing at the torque won't cut it. Don't operate for 24 hours. (many industrial tapers are spec'd to be loctited)

FlyBoyMark · May 6, 2002

Re: How to weld a flywheel on a 1976 Horse Johnson 55

And as an addendum....from a professional weldor......DO NOT WELD UNLESS YOU HAVE SUICIDAL TENADACIES WHEN THE CRANK SHEARS.........Metal frisbies REALLY hurt!

Joesnowmobiles · May 7, 2002

Re: How to weld a flywheel on a 1976 Horse Johnson 55

Thanks guys for all the suggestions I will work on it this weekend hopefully and see if it will work. I really appreciate all your help. Thanks Joe

How to weld a flywheel on a 1976 Horse Johnson 55

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