79 Evinrude 140hp Linkage Slip

urugol

Seaman Apprentice
Joined
Nov 11, 2012
Messages
47
I have a 79 Evinrude 140hp I just replaced my lower unit with a supposedly "good" used one. The powerhead on my engine is actually a 77, which had the threaded rod link for the gearbox so I upgraded to the new model, changed the intake manifold and obtained the correct linkages to do the conversion. The issue I have is that the engine jolts in and out of forward consistently every few seconds. Neutral and reverse are fine with no issues. I drove it with the cowling off to observe the gear linkage and I can clearly see the shift rod pulling in the opposite direction every few seconds. I have been reading this wonderful forum in regards to dog clutch and linkage adjustments. I'm unsure where to look first but it has been off, I changed the impeller and water pump but never did the link rod height ajustment. Could that be the problem, or the linkage or does it sound like I have a crap lower on my hands?

I should add I tried to adjust the hell out of my cable so it would pull hard on the rod, to the point that it wouldn't engage in reverse - still no good it just pulls back on it. It also runs great adjusted out of the water, on the earmuffs with no load the prop spins in forward and reverse and neutral is perfect. This only happens under load in forward only.

Any help greatly appreciated!
 

boobie

Supreme Mariner
Joined
Nov 5, 2009
Messages
20,826
Re: 79 Evinrude 140hp Linkage Slip

Sounds like a bad fwd gr and shift dog. Check the top secret files at the beginning of this forum for shift rod heights.
 

urugol

Seaman Apprentice
Joined
Nov 11, 2012
Messages
47
Re: 79 Evinrude 140hp Linkage Slip

Sounds like a bad fwd gr and shift dog. Check the top secret files at the beginning of this forum for shift rod heights.

I hope not :grumpy:

I will take a look and try the height thing first if that fails I'll just get another lower unit I guess :facepalm:
 
Top