"Walking" Flywheel...

[Big Jay]

Hello again everyone...

Still working on my '68 Evinrude Big Twin and I once again have a question I couldn't find an answer to in the forum.

I just inspected my coils, condensers and points. I pulled the flywheel expecting the worst, but to my surprise it was all new. So I cleaned the area up cause there was some dirt around and some oil too. Regapped the points and then wiped them down with Isopropanol. Finally got the coils sitting right so they weren't rubbing the flywheel and went to tighten it all down....

This is when I realized the flywheel would rock under my hands if I wanted it to. Is this normal? Will it be ok once it's torqued down?

Also I noticed the crankshaft and the flywheel hub both had 3 or so spots of rust / deterioration on them:facepalm:... I cleaned it up with a brass brush and Isopropanol to degrease it, but I think it might be causing my issue....


Any help would be great guys.... thanks

 

[oldman570]

Re: "Walking" Flywheel...

It should be good when the flywheel is torked down. A search on the web for Leroys ramblings should get you more info on the older two stroke twins, and is very easy to understand.

 

[Chris1956]

Re: "Walking" Flywheel...

Jay, There is a torque value for the flywheel nut. Make sure the woodruff key is installed properly, and the flywheel fits snugly. Now torque it down. The torque value is likely a few ft-lbs over 100, but someone on this forum will know the exact value.

 

[Big Jay]

Re: "Walking" Flywheel...

Thanks so much guys.... I figured torquing it down would take care of it. However... I'm now noticing the armature plate has a little play side to side, this is worrisome because I had to move the coils in from the boss edge to compensate and keep them from rubbing.

This will likely effect performance and spark value. Is there a way to shore it up? Both mounting screw are tight...

Gawd, I hope this engine isn't a write-off, I fell in love with her already and the wife won't let me get another one

 

[kfa4303]

Re: "Walking" Flywheel...

HI Big Jay. Don't worry, it's not uncommon for there to be some play in the magneto plate. Here are some great links to help you get the old motor tuned up. What is the exact hp, btw?

http://www.duckworksmagazine.com/04/s/columns/max/24/index.cfm

http://www.outboard-boat-motor-repa...on 3 HP 1952-1967 Ignition System Tune-up.htm

 

[Big Jay]

Re: "Walking" Flywheel...

Hey KFA....

Thanks for the great links! Very cool!


My old girl is a big twin 40 hp 1968, 40853A. I just love the look of her, she's been sitting on the transom of an old Traveller boat I'm also restoring in someones lawn with no trailer for 5 years or so. In Canada that means 5 winters (brrr). I've been tinkering for a month now and am just about ready to start her up. I found a few ounces of water in the lower unit while changing the fluid (first heart-attack) but soon realized it was likely due to the fill and vent washers being shot (they leaked after I changed the fluid). So I changed them and it's sealed up now. I then gave it a carb kit and changed a few rotten wires. Found a spare slow speed needle valve in the rear exhaust cover (hmm) after pulling it off to retrieve a fallen nut...

So far it's been full of surprises, some good some bad. But the loose magneto scared me.

 

[tx1961whaler]

Re: "Walking" Flywheel...

105 ft-lbs for the flywheel torque, with a torque wrench. No guessing on this one.

 

[Big Jay]

Re: "Walking" Flywheel...

Jay, There is a torque value for the flywheel nut. Make sure the woodruff key is installed properly, and the flywheel fits snugly. Now torque it down. The torque value is likely a few ft-lbs over 100, but someone on this forum will know the exact value.

Chris... this is my problem:

The key is in right, and I lower the flywheel down and instead of snugging up, it wobbles back and forth until I torque it down a little.

I need to know if this is normal.

TIA, Jason

 

[Big Jay]

Re: "Walking" Flywheel...

It should be good when the flywheel is torked down. A search on the web for Leroys ramblings should get you more info on the older two stroke twins, and is very easy to understand.

Thanks old man (feels a little weird calling you that... lol) I've seen Lerroy's Ramblings before and he is awesome for sure. I used his page to get my '81 Johnson 9.9 going.

I'm worried the flywheel won't torque down straight with the wobble in it....

 

[Big Jay]

Re: "Walking" Flywheel...

Thanks tx...

I figured someone might come up with the right amount of torque here...

 

[boobie]

Re: "Walking" Flywheel...

If it has the proper flywheel key and is installed correctly and the tapers are clean and shiney, the flywheel should sit down on the crank with no wobble at all. If you have to tighten the flywheel nut to take the wobble out, there's something wrong.

 

[Big Jay]

Re: "Walking" Flywheel...

If it has the proper flywheel key and is installed correctly and the tapers are clean and shiney, the flywheel should sit down on the crank with no wobble at all. If you have to tighten the flywheel nut to take the wobble out, there's something wrong.

Ok ...

So, what's the wrong way and the right way to install the flywheel key?

Round-side-in is how I found it, was it wrong before I got to it maybe?

Feeling a little green here all of a sudden:redface:

 

[seahorse5]

Re: "Walking" Flywheel...

The flywheel taper and the crankshaft taper must match exactly. Wobble means something is keeping it apart. The keyway flat side faces straight up and down, not along the taper of the crank.

Years ago we would use valve lapping compound to match the crank to the flywheel. In fact the taper is what holds the flywheel in place and the key is what locates it in the correct postion.

 

[bwkre]

Re: "Walking" Flywheel...

Something is wrong. The flywheel should become snug before you even start tightening the nut. Check the taper of the two pieces. Any marks may indicate that they may have spun on eachother at some time from a broken key or a loose nut. It is possible you could have the wrong flywheei? Also check the timing cam that sits below the flywheel. If it is not seated properly or it is the wrong one, the flywheel will not fit the crank taper properly. If all else fails take it to a machine shop & have them check the tapers. Good luck.

 

[bwkre]

Re: "Walking" Flywheel...

Did you have to use a puller to remove the flywheel? It should have required some effort to remove. If it came off easily, that is a sure indication of trouble. Most flywheels pop off once the puller gets tigt enough.

 

[Blacksting]

Re: "Walking" Flywheel...

i cant imagine how , but is the flywheel bent or warped ? or the same for the crankshaft ? ,....bwkre might be onto something , maybe the wrong flywheel .

 

[bwkre]

Re: "Walking" Flywheel...

All u need is to loose a couple thousand's of an inch from spinning and it wont fit. Look under the cam for metal. L

 

[bwkre]

Re: "Walking" Flywheel...

All it takes is a couple thousands of an inch wear to prevent the flywheel from fitting the taper. Loolk under the cam for signs of metal. I would think the wear will be in the flywheel half as the crank will be a much harder metal.

 

[Big Jay]

Re: "Walking" Flywheel...

All it takes is a couple thousands of an inch wear to prevent the flywheel from fitting the taper. Loolk under the cam for signs of metal. I would think the wear will be in the flywheel half as the crank will be a much harder metal.

There's not metal shavings indicative of a spun key, but there is erosion between the tapers as you can see from these pics. Should it not just fit like a glove once torqued down again?

 

[Big Jay]

Re: "Walking" Flywheel...

The flywheel did require a puller to get off. It didn't however "pop" off so much as gradually let go