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1989 50hp 3 Cylinder Lower Unit issue

B

BAS

Member
1989 50hp 3 Cylinder jumps right up normally then revs high while losing speed. Not bogging down, the opposite, it revs high and loses speed..
-Ignition and fuel systems check out and were just serviced.
-Engine operates in Fwd and Rev
-Shifts with no problems
-Prop turns freely in neutral, no binding, grinding or noise.
-Tried to turn the prop by hand while holding flywheel, it is tight in the direction that it is in gear for (maybe a 1/4-1/2 of play in hub).
-When holding the flywheel and turning to the opposite direction of shift direction, the prop turns but clicks internally in the gearcase.
-Gear case oil is dark but smells like petrol, not burned, and does not have shavings or metallics in it.

I praying for a spun hub here guys...:rolleyes:
 
Thought I would add a pic of the gear case oil. Once again, no metalics or foul odor. IMG_1754.jpg
 
Being I think it is important to post results for other experiencing the same issues, here you geaux:
I try to give detailed info on the issue and the setup but in this case failed to mention the manual jackplate installed on the boat. (Set on lowest setting) After thinking about it I thought it sounded like a cavitation/ventilation (C/V from now on, please argue about correct terminology among yourselves :) )issue being there were no other tell tail signs. I inspected the plate and engine setup and using a straight edge clamped to the top of the C/V plate on the engine that it was set about 2" above the bottom of the boat. I was able to lower the engine on the jackplate by about 1.75" and did so. The top of the C/V plate is now a negligible height above the bottom of the boat.
Took the boat out for a run and tested, straight, turns, hole shots and slightly choppy water and the problem is gone.
It was a C/V issue. Thank you for the replies and I encourage others to post results after posting a question and getting answers.
 
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