Sheared off flywheel bolt (1957 Scott Atwater 3875 10HP)

[chad101]

I was given a 1957 Scott Atwater (10HP) outboard; which has been sitting for so long, the pistons are seized.

Two cans of WD40 and a week later, the pistons finally break free. But I ended up shearing off the flywheel bolt in the process... (nothing was used for additional leverage, All I had was a hand held ratchet).

I not looking to sink a ton of money into an outboard which hasn't ran in 20 years. Should I scrap the engine or is this a cheap fix?

Also, do I need a special tool to remove the flywheel cover (see picture). I can't get this SOB off for the life of me!!!

 

[Lyle29464]

Re: Sheared off flywheel bolt (1957 Scott Atwater 3875 10HP)

Many ways to remove it. Start with the easy stuff first. I would cut a straight slot in it. (not tapered) and try a mix of mild heat to draw in the penetrating oil, may do the heat then oil 5 to 10 times. trying to get oil down the shaft and keyway. Then try to work it back and forth with a non tapered screw driver. If you wedge something between the flywheel and block to lift the crank you can tap on the bolt a bit. If you hit it hard or hit it with the crank bottomed out you can ruin it. Some people prefer to file the bolt to fit a 6 sided socket or flat for an adjustable wrench.

 

[GreenHornet763]

Re: Sheared off flywheel bolt (1957 Scott Atwater 3875 10HP)

I used a flywheel puller kit, mainly used only the cone shaped socket to hit the shaft and it poped open right away.

 

[chad101]

Re: Sheared off flywheel bolt (1957 Scott Atwater 3875 10HP)

Thanks for the info I greatly appreciate it.

I have some good news, after getting the pistons loosened up real good I wrapped a rope around the flywheel and gave it a good tug. I?m getting an excellent spark from both plugs!

I just want make sure I didn?t cause any confusion from my first post. I broke off what I believe is the threaded tip of the shaft that the nut screws onto. I think this rod extends all the way down though the flywheel into the lower unit?

Am I correct? Please tell me I?m not or that it?s fixable.

 

[F_R]

Re: Sheared off flywheel bolt (1957 Scott Atwater 3875 10HP)

That is the crankshaft, one of the most expensive parts of the motor. Unless you can find a parts motor, you now have a parts motor for somebody else.

 

[narwhals]

Re: Sheared off flywheel bolt (1957 Scott Atwater 3875 10HP)

if you know someone who is a competent welder they should be able to mate a small piece of threaded rod or a grade 8 piece of bolt. just a thought before you start parting it out. 10 bucks and a case of beer for a quick weld might do the trick.

 

[chad101]

Re: Sheared off flywheel bolt (1957 Scott Atwater 3875 10HP)

Not the news I was looking for. I'll see what I can do about finding a welder. :facepalm: