Smoky Merc 150

Old 05-28-2004, 09:52 PM
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Default Smoky Merc 150

Took one of our Fire/Rescue Boats out today. 1998 Edgewater 185 with 1998 150 Mercury with new powerhead. Runs rough and smokes when idling up thru 2000 RPM. Runs great on plane and WOT. It would cut out at idle so they set the idle up. Now it seems like it runs rich. Also has an oil sheen after shutdown. Any clues on what might be causing this.

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Old 05-28-2004, 10:04 PM
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Default RE: Smoky Merc 150

Check out the linkage to the on engine to the oil pump.At idle the linkage should allow the 1st mark on the cam on the oil pump to align with the fixed mark on the pump.At WOT the 3rd mark should align with the fixed mark to give a 50(gas) to 1(oil) mix.
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Old 05-28-2004, 10:11 PM
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Default RE: Smoky Merc 150

Sound like a fuel mixture problem. Probably too much fuel. Same thing happened to one of my 150 yams and we found that one of the two fuel pumps had a torn diaphram. Changed them both out and that solved the problem.
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Old 05-30-2004, 06:37 AM
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Default RE: Smoky Merc 150

check with the guys who did the power head.
I'm thinking extra break-in oil...
perhaps they added extra oil to the gas
or they may have set it rich for break in, with the intent of adjusting after 20 hoours or so?

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