MERCURY 150hp Carbonized

mav6759

Chief Petty Officer
Joined
Jun 25, 2007
Messages
489
I have a Mercury 150hp that cut off on me on the lake. It would ran fine for about 3 hours and it just died. I had it looked at and I was told that the motor was Carbonized and when it gets hot, its going to die. I guess my question would be, have anyone heard of that, and if so is there anything I can do to clean it out. I just bought the boat about a month ago.

Thanks Mav
 

444

Senior Chief Petty Officer
Joined
Jul 16, 2010
Messages
704
Re: MERCURY 150hp Carbonized

That doesn't make any sense at all. Take it to someone else. If your motor just up and died after 3 hours of running fine, something else is the problem. If you hook the engine up to the garden hose, will it start and run now?
 

mav6759

Chief Petty Officer
Joined
Jun 25, 2007
Messages
489
Re: MERCURY 150hp Carbonized

Yes it will start each time. so I took it to a Mercury dealership, after looking at it they said it was built up in carbon cause low compression, therefore stopping the motor from running. They said there was nothing they could do, about the carbon.
 

oldman570

Lieutenant Commander
Joined
Mar 25, 2011
Messages
1,615
Re: MERCURY 150hp Carbonized

Iam with 444 on this as carbon in th motor should not make a motor just quit running. I would take it to another shop and have them check it over and look at the piston skirts for scoring if need be along with a compression test. What year motor and sr# is it?
Oldman570
 

oldman570

Lieutenant Commander
Joined
Mar 25, 2011
Messages
1,615
Re: MERCURY 150hp Carbonized

If the compression is low you definately have problems with the motor being sound. Carbon can be cleaned up with a can of Power tune sold at Merc dealers, or automatic trans fluid left to set for a few days. Tip the motor all the way up an remove the plugs and shoot the power tune or trans fluid, in the cyclenders. After a day or so tilt the motor down and ground all the plug wires, the spin the motor over till all the gunk is blowed out of the motor. You need to do this outside as the gunk will fly all over. Then run a compression test and see just what the readings are. Remember a 10 percent diffrance will indicate that the motor might need a rebuild.
Oldman570
 

Mi duckdown

Commander
Joined
Apr 14, 2007
Messages
2,575
Re: MERCURY 150hp Carbonized

I WOULD check compression first before doing anything to get a base line on all cylinders.
 
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