1962 Johnson 40hp won't turn over

[awh420]

I have a 1962 johnson 40 hp w/ electric shift(2-stroke). I know nothing about motors. with some help, I cleaned up the starter and rebuild the carburator. If the plugs are out, the flywheel with turn fairly easy with the starter or the pull start. But when the plugs are in, it will only turn once with the pull start and its very difficult, won't turn at all with the starter. I figured maybe the exhaust ports were clogged but when I removed the exhaust cover, and had a view right into the cylinders, it did the same thing. any suggestions?

 

[Joe Reeves]

Re: 1962 Johnson 40hp won't turn over

What spark plugs are you using?

Has anyone milled, shaved any metal off of the cylinder head and/or block?

 

[awh420]

Re: 1962 Johnson 40hp won't turn over

the spark plugs were in the motor when I got it... they say AC m44c marine on them. I don't know if the motor was shaved at all because i got it used off of craigslist. when I got it he said it ran but you never know.

 

[tashasdaddy]

Re: 1962 Johnson 40hp won't turn over

you should be using Champion

Champion Plugs. 40hp 1960 - 1973 J4C gapped .030

the piston could be hitting the end of the plug.

 

[R.Johnson]

Re: 1962 Johnson 40hp won't turn over

If the piston is hitting the plug, the gap will be closed,

 

[F_R]

Re: 1962 Johnson 40hp won't turn over

M44C is same as J6J. Piston shouldn't hit that.

 

[sprattoo]

Re: 1962 Johnson 40hp won't turn over

I still think the Champions are a good suggestion for anything regardless of the issue. I have tried other brands, and even though Evinrude/Johnson suggests the NGCs Go with a champion plug anyway.

They fire better, run cleaner and last longer.

 

[Joe Reeves]

Re: 1962 Johnson 40hp won't turn over

awh420....... With the spark plugs installed, and with the manual starter, can you very slowly pull the engine over more than once, OR do you get the sensation that you're pulling the engine thru just a short ways then it locks up solid?

If it locks up solid, remove the spark plugs so that you can inspect the electrodes for impact marks.

 

[awh420]

Re: 1962 Johnson 40hp won't turn over

I'm sure the plugs don't have anything to do with the issue. It will pull more than once but its very difficult. I just don't understand why it would make that much of a difference with the plugs being in because it seems like the pressure can escape easily through the exhaust port and obviously when they're out, theres no pressure at all so its easy to turn.

 

[tmcalavy]

Re: 1962 Johnson 40hp won't turn over

Well those puppies have a lot of compression. If the starter barely cranks it with the plugs out, pull it and clean all connections and oil it. Then take the recoil off and turn the flywheel by hand. If it seems solid and doesn't wobble, pull the flywheel and check the key that holds it to the crankshaft. Put it back on, and make sure the coils aren't dragging on the flywheel...turn the flywheel and listen for a slight scraping sound. That means a coil is not aligned right. If the flywheel/coils check out okay, put some penetrating oil in the cylinders, clean all block/starter contact points with a wire brush, reinstall the starter and make sure the battery connectioins are clean/good. Did the same things to a 57 Big Twin 35 hp and it made a world of difference...fires right up with the starter. Pulling it over with the recoil is a pain...so protect your shoulders/arms and get the starter working again. Rotator cuff repair bites.

 

[Elbo]

Re: 1962 Johnson 40hp won't turn over

Sounds to me like you got some real good compression.Starter could be bad or maybe out of line.But pulling that by hand takes a real hoss!

 

[Kevin 393]

Re: 1962 Johnson 40hp won't turn over

check the ground make sure it is clean and tight and that the cabel & conector are good I had the same prob with my 40 hp and the ground cable and conector was not good it rolled but was slow till it melted the ground cabel from the conector!! hope this helps