Soot from engine exhaust on start-up

[richard Walker]

When I start the engine (after being off for several days or an hour) black soot is ejected from the exhaust. This floats on the surface of the water for a short time and then eventually sinks. I do not see any evidence of oil with the ejected material. The engine runs fine and there is no smoke from the exhaust during idle or normal running at ~2500 RPM.Has anybody any idea why this suddenly started and what is the cause / solution?I have a total of 150 hours on the engine.

 

[Gary Malcolmson]

Exhaust Soot

Richard,I've not experienced what you describe (if I have I haven't seen it, my 2003 is currently at 125 hours) but I bet what you're seeing is carbon buildup being blown out. I've heard reports that if you don't give the engine a good workout you can build up carbon deposits in the exhaust elbow. This can close up the elbow to the extent that you'll not be able to get any power from the motor. So, apparently it is best to give the engine a good workout (after a decent warm-up period) and don't "baby" it. This may not be the case in your situation but I thought that I'd mention it. You might want to take a good motoring boat ride and clean things out a bit and see if the soot is still there the next time you start after it sits for a few days.Let us know what you find.Happy Sailing,GaryC310 #230 "Rhythm"