I am looking for thoughts/suggestions about how to cure the exhaust smoke that I am getting. If I motor at 1800 rpm the exhaust smoke trails the boat by about 1 ft. If I increase rpm to 2500, the engine heat rises to 195 and the exhaust smoke trails the boat by about 3 ft. I have replace the impeller, replaced hoses, and cleaned the heat exchanger. The boat is a 1988 Cat 36, with universal 25xp. Thanks Chuck
smoking exhaust
- Thread starter FINKCPA
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Smoke or Water Vapor
Chuck, Sounds like you may be seeing the water vapor from your engine cooling system fogging as it exits with the exhaust. Does it dissipate completely or do you leave a trail of actual exhaust smoke as you motor along. If your engine is smoking, burning oil or running inefficiently you should see the 'cloud' marking your path. Let's hope it is just the water vapor!! No need to cure that! fair winds, Dave
Chuck, Sounds like you may be seeing the water vapor from your engine cooling system fogging as it exits with the exhaust. Does it dissipate completely or do you leave a trail of actual exhaust smoke as you motor along. If your engine is smoking, burning oil or running inefficiently you should see the 'cloud' marking your path. Let's hope it is just the water vapor!! No need to cure that! fair winds, Dave
Chuck: I assume the color of the smoke is white, which is steam. If it has a blue cast, it is oil. Are you getting a flow out the stern - it should spit out a couple of feet? If it is spitting then part of the problem is that you did not go far enough in the cleaning process. AFTER the heat exchanger, a flow of water goes into a EXHAUST RISER, which hangs off the exhaust manifold. The water entering the exhaust riser cools the exhaust before it goes to the aqua lift muffler. In my case (25XP), I did everything you did to no avail. It was very frustrating so I started looking further and when I tried to blow through the hose to the exhaust riser I found it was plugged. The plug was at a nipple on the exhaust riser but when I replaced the entire exhaust riser (about $175) I found the new one was lighter than the old one. That was because all the pieces from blown impellors etc ended up there. If you do not have an exhaust riser and instead have a "black pipe" setup there is probably a clog some where in the black pipe system. The problem with the black pipe is it starts to rust 2 seconds after it is installed.
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