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1975 Johnson 115 won’t start after overheating

M

Mikk Wardwell

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The other night, while steaming home after an evening of bass fishing, my 1975 Johnson 115hp started losing power and then shut off…..went from about 40 knots, to 5 knots, to dead in the water within about 7-10 seconds. As I started back toward the motor to see what happened I could see a buncha steam and hear water boiling. So I pulled off the cowling, to help it cool down, and finished the trip to the dock with my trolling motor. Back at the dock I tried starting up the 115 to check the telltale but it wouldn’t fire. The next day I changed the impeller/housing and the lower unit oil and took it back to the lake for a test run but, again, it wouldn’t even begin to fire. Checked all connections n found a small 30a fuse that was blown. Still wouldn’t fire. Used a multimeter and found appropriate readings from the starter all the way to the coils, but no spark from the plugs. Btw, I also changed the plugs when I did the impeller and lower unit. Any ideas on where to go from here? Thank you, in advance, and happy boating!
 
Ok, so I bought a compression tester….also, boobie, there’s absolutely no spark from any plug…and it’s not reading any compression whatsoever. Yet, I can feel it trying to push my finger off the cylinder. I didn’t even remember I still had it but, while looking in the basement for something completely unrelated, I found that I own a Clymer Evinrude/Johnson outboard shop manual for ‘73-‘90, 48-235hp. I started doing some ignition tests and everything is good up to and including the safety switch.
 
Update and more questions: I ended up finding a really good deal on a newer 115….the guy said it was an ‘88 or ‘89….that allegedly needed only a prop and a solenoid. Being that I had several props and my older motor to scavenge parts form, I bought it. Got it home and started looking into exactly what I had. Turns out it’s a 1988 Johnson 88hp with V-4 115hp cowling. Whatever, a lot of the parts are interchangeable. Ended up needing the solenoid and starter from my old 115hp. Nbd. Then I try the prop. For some reason the 88hp has a 15 spline, though everything I’ve read says it should be a 13 spline like my 115 has. My question; can I use the shaft from my 1975 115hp on my 1988 88hp, so I can use 1 of my props? Or do I need a new prop? If I need a new prop, what size and pitch should I get? I usually run wide open, since when I get to where I’m going I use my elec trolling motor, and I occasionally pull my kids on a tube. Never do I troll and rarely do I run at low speeds.
 
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