1992 Merc exhaust fumes problem help!!

[ducksdemise]

I am having issues with my engine it is a 1992 merc 5.0l V8 200hp. It is on a 1992 24' Thompson Fishermen with a convertible top. When running full throttle engine runs great does 34 mph. When trolling 1.5 to 2.8 mph I get bad exhaust fumes onboard so bad I cant stand it. I have tried running blower all the time with no luck. I have had a compression test done 5 cylinders read 135 1@130 1@ 140 & 1@145. Also had a leak down test done cylinders read as follows 20%,18%,14%,18%,12%,18%,14%,16%. Marina that has donee the tests say all is normal for an engine with 945hrs on it.Does anyone have any ideas about the fumes any info will be helpful.
Thanks,
Jim

 

[a70eliminator]

Re: 1992 Merc exhaust fumes problem help!!

I get that too, depending on the wind direction, if trolling into the wind all is fine, but make a turn with the wind and the exhaust fumes seem to follow.

 

[Don S]

Re: 1992 Merc exhaust fumes problem help!!

You may not have a problem with the engine. Wind direction, lack of wind at all, station wagon effect, all can cause exhaust to come up over your transom and into the boat.
Needing a full tunup, carb idle mixture, choke settings ant the correct operation of engine can only minimize fumes, not stop them.