Exhaust Blackens the Stern

[Joe Luciano]

I have a 1987 C-30 with the Universal M25XP diesel. One problem I've been having is that the exhaust exiting the tail pipe blackens the stern. It seems to do this primarily when motoring close to hull speed and the exhaust is exiting very close and into the wake of the boat. This creates turbulence, splatter and after just a short time, a blackened stern. It seems as though the exhaust tail pipe should be about two inches higher and there would be no problem. My engine runs fine and performance is great. Does anyone else have this problem or am I the only one that gets tired of cleaning the stern all the time?

 

[Roger]

Me too

I have an '85, C27, and have exactly the same problem. I have found that "Barkeeper's Friend", its a non-abrasive scouring powder works well at getting the black off, but what a hassle.

 

[Gary Jensen]

diesel smoke on stern

My 36 was the same way. I battled the problem only to get tired of it. Someone pointed out a product by Casterol. (Its a degreaser found at Wallmart and Kmart) I used it on the stern with exceptional results. When I got it completely clean, I waxed it and that helped too...

 

[Mike Adkins]

blackend stern

I had the same problem on a C-30, found the only way to solve it was to back off on the RPM to around 1800, no black stern.