My exaust blows an unusual amount of white smoke and the overheat alarm sounds if I run the engine at a high RPM for 5 minutes. The alarm will not sound if running at 1/2 RPM. Any suggestions? 1978-30ft. with Yanmar YSM12.
White Smoke
- Thread starter kevin d
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Sounds like a mixing elbow
The likely cause is a clogged mixing elbow but you should also check for a partially clogged thru hull or strainer,and a damaged impeller with one or more vanes mising. More serious causes might include a blown head gasket. Good Luck!
The likely cause is a clogged mixing elbow but you should also check for a partially clogged thru hull or strainer,and a damaged impeller with one or more vanes mising. More serious causes might include a blown head gasket. Good Luck!
Mixing elbow
The same thing happened to me. It was the mixing elbow. It is no easy task to change especially if you have had modifications for a heat exchanger.
The same thing happened to me. It was the mixing elbow. It is no easy task to change especially if you have had modifications for a heat exchanger.
New elbow
Thanks all. I've ordered the elbow with all needed parts & gaskets leading up to the motor just in case the years and salt had an effect on everything else. Will post progress.
Thanks all. I've ordered the elbow with all needed parts & gaskets leading up to the motor just in case the years and salt had an effect on everything else. Will post progress.
Mixing Elbow? - I Don't Know.
Usually the mixing elbow being clogged will result in backpressure and cause the engine to smoke black/grey. White smoke is often steam and the result of some sort of clog (or bad impeller) in the raw water intake system. Since you bought the parts, change the elbow. It can't hurt. But also check from your intake to the impeller for a restriction or blockage. Check each segment of the raw water intake system (thru-hull, hoses, elbows, strainer, impeller)for a restriction. Good Luck and keep us posted.
Usually the mixing elbow being clogged will result in backpressure and cause the engine to smoke black/grey. White smoke is often steam and the result of some sort of clog (or bad impeller) in the raw water intake system. Since you bought the parts, change the elbow. It can't hurt. But also check from your intake to the impeller for a restriction or blockage. Check each segment of the raw water intake system (thru-hull, hoses, elbows, strainer, impeller)for a restriction. Good Luck and keep us posted.
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