1981 35HP Johnson jumps out of gear + need help checking compression

[speedcat2000]

I have a 1981 Johnson 35HP. I've spoken to several mechanics and explained the issue where it jumps out of gear. The consensus seems to be one of two things:

1) Prop connection (?) is broken so prop won't spin with motor
2) Either the forward gear, or the fwd gear clutch, or both, are stripped and need replaced.

Most people think it will be 2) and will be $300 in parts alone. I live in Seattle & wondering if there are any cheaper options. Also need a good outboard mechanic as I am pretty clueless myself. The shops around here seem to want between $75-$100 per hour, not sure I can justify the end-run cost on these old motors.

(edited.. found the "comp test sticky" - thanks).

Also have 1975 85HP Johnson, need compression test. If anyone has a good compression tester I could borrow in the Seattle area I'd be psyched. Also would gladly pay for some help with either motor.

Sorry to lump several questions into one thread. Thanks for any help you can provide with these questions.

Cheers,
Jeremy W.
Seattle, WA

 

[jbjennings]

Re: 1981 35HP Johnson jumps out of gear + need help checking compression

Jeremy,
What does your motor do when it jumps out of gear? Does it feel like you hit a stump and kind of "bang" out of gear and the motor revs up really high until you shut it down, or.....does it gently rev up high and the motor quits pushing? If it's the "bang", "stump-hitting" jump out of gear thing, then it's the clutch dog or the shifter is out of adjustment. If the motor is not new to you and you have never fooled with the shifter handle, then it's most likely the clutch dog. If it's a gently slip, then it's probably a spun prop hub, which is a fairly cheap fix at a prop shop. I doubt there's a cheap way to get out of a clutch dog problem, since GOOD used lower units are hard to find for those motors since they're so popular.

You can get a $20 compression tester at any autoparts store and check the compression on your 85hp. It just screws into the spark plug holes. Heck, find a grumpy old neighbor that works on his own stuff and borrow his!

Just some ideas,
JBJ

 

[speedcat2000]

Re: 1981 35HP Johnson jumps out of gear + need help checking compression

Thanks JBJ - I guess I'll buy "another" tool. Man that spark plug tester I got at Schucks was a real POS. Fell apart immediately, and looks like it was never actually hooked up correctly anyways (copper wire did not appear to be fixed to the metal housing that connects to the plug itself).

RE: the gears - I actually never experienced the problem - own this boat with a buddy and am just going on his description.

Is there any way to rule out the "shifter out of adjustment" issue? I think my buddy messed with some of the adjusters last year...

thanks!

 

[speedcat2000]

Re: 1981 35HP Johnson jumps out of gear + need help checking compression

just to follow up, I asked my buddy who ran the boat when it was having this problem last year, and his response was that it would go fine in reverse or forward at low speeds, but at higher speeds it just revved up but stopped forward motion. I think this sounds more like the "spun prop hub" issue - which is great news!

Thanks