On 9/24 I asked the group about spme overheating problems (see Overheating 3GMF), got some answer and thanks to the help, I found out and fixed the problem (See Overheating 3GMF, Tks of 9/25). In my message of 9/25, I mentioned that I had solved the overheating problem, but I was still getting some white smoke. That smoke is now getting much worse, is dry (definitely not steam), and definitely has a combustion smell to it, although the engine does not consume enough lube oil to be noticeable. The higher the RPM, the worse it gets, and over 2500 the engine seems to be sluggish, although it always starts without hesitation. I have changed both fuel filters (Racor primary and Yanmar for the other)and bled system, and also changed oil and filter twice in the last 4 weeks (with no signs of water in the crankcase) I have gone to the archives, but did not see a post pertinent to this problem, although there are some mentions of bad fuel in the tank (algae ?) sometimes creating a problem like that. Some mentions as well of mixing elbow problems, but I am no longer loosing coolant and the engine does not overheat. The boat is getting on the hard this Sunday, but I want to look for the problem as soon as possible. If Gordon or anybody else could point me in the right direction, I sure would like to solve that before the boat is covered with a thick coat of the white stuff. Thanks for the help.