Clutch dog or prop hub?

badgerbacker

Cadet
Joined
Feb 7, 2012
Messages
9
I have a 1992, 75 horspower, 3 cylinder, 2 stroke that runs great but recently developed an issue slipping out of gear under high loads.
Everything is fine until near WOT when running into a heavy swell. The motor slips out off gear (without any clunking or banging) but if I shift into neutral and then ease back on throttle it is fine. It also "jumps" when in reverse past 1/4 throttle, as if it is popping out of gear and going back into gear. (it has had that issue for awhile)
I am guessing the "forward" issue is the prop hub, as I run the engine around heavy kelp areas and have accidentally wrapped up the prop a few times.
I know I can check to see if the prop hub is slipping (pull prop, mark hub and prop with line, check for movement) but is there another way to narrow down the cause without trailering, launching and then running the boat? I would like to take care of the issue before launching the baot again.
Thanks!
 

eavega

Lieutenant
Joined
Apr 29, 2008
Messages
1,377
Re: Clutch dog or prop hub?

On the one hand, I had a buddy of mine with a 2006 Mercury 115 HP with exactly the same symptoms. I could've sworn up and down it was a clutch issue. Turned out it was a spun hub.

Rgds
 

MH Hawker

Vice Admiral
Joined
Jul 13, 2011
Messages
5,516
Re: Clutch dog or prop hub?

That or the shift shaft is out of measurment and is not fully engaging the gear set.. That will cause one to jump in and out of gear.
 

aussieflash

Lieutenant Junior Grade
Joined
Feb 5, 2011
Messages
1,004
Re: Clutch dog or prop hub?

im going with spun prop.Draw the line and go for a spin.
 

GPSDuckHunter

Seaman Apprentice
Joined
Sep 28, 2010
Messages
37
Re: Clutch dog or prop hub?

That or the shift shaft is out of measurment and is not fully engaging the gear set.. That will cause one to jump in and out of gear.

I'm more in agreement that the shift shaft needs adjustment. Generally the spun hub problem shows up as soon as you start pushing the throttle harder. But I also agree its easier to test spun hub than to tinker with shift shaft adjustment.
 
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