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Mercrusier 165 hp loss of prop power under a load

D

Dylanashultz

New member
So I’ve got this old 165hp with the 4.1 inline 6 motor and the other day I was on the water about 1/4 throttle and out of no where it acted like it went into neutral. Rpms stayed at 1/4 throttle I just wasn’t going anywhere. I noticed grey smoke from where the engine and the outboard part meet on the inside. Smelled like burnt rubber. So I shut it down for about 5 minutes and tried again. I could then do idle speed but as soon as I got on the throttle a bit I lost it again. So I get it home and I put the muffs on and let it run for bit then I got on he throttle again went back and that prop was spinning quite fast. I’m new to boats but have worked on cars so I’m a little mechanically inclined but I’m lost on what to do here. Any help would be wonderful. Thank you all!
 
Coupler between engine and out drive is slipping, that's the burnt rubber you're smelling. Will spin fine out of the water with no load on it, different story trying to push a boat.

To change it you need to lift the engine up and forward forward enough to remove the flywheel cover to access it. Not a big job if you can lift the engine.
 
Oh My gawd! Please please please remove the prop when you are running the boat out of the water on the muffs, Especially if you are not able to see back there from the helm station! It takes like 30 seconds and can save a hand or...
 
Dieter said:
Coupler between engine and out drive is slipping, that's the burnt rubber you're smelling. Will spin fine out of the water with no load on it, different story trying to push a boat.

To change it you need to lift the engine up and forward forward enough to remove the flywheel cover to access it. Not a big job if you can lift the engine.
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So is the coupler like a clutch? And is that what it’s called so I can find the replacement part?
 
Coupler isn't like a clutch exactly ties the flywheel to the outdrive driveshaft allows a little movement between the two. there is rubber holding the splined female piece to the coupler. They can slip or break over time or if there is an impact lessen the damage to the driveline by breaking. Not unusual for the age (assumed your engine is pre 1982). Search above in parts by your engine number, yes its called a coupler. You need to pull the outdrive and lift or remove engine to get at it. Make sure to check you alignment as this is the number one cause of coupler failure like if motor mounts sag.
 
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