Yanmar 300 6LP Smoke

[jpwrist]

Need help with bad smoking Yanmar Diesel.

When I start up my Yanmar 300 hp 6LP (700 hours) on my 2001, 28 foot Tournamnet Express it smokes so badly that I hurridly leave the dock and avoid all eye contact with other boat owners. My wife says it looks whitish, but I see a slight tinge of light blue. It appears to dissapate when it runs at 75% of max, but when I shut her down and gun her in neutral, it pours out. I have had this problem for a number of years and it appears to be getting worse. I just had the valve stem seals replaced (two years ago, but only 100 hours ago) and also just had the injectors serviced/rebuilt. (1 hour ago). I had hoped that the last item would correct the problem, but it didn't. The diesel fuel is about 8 months old and the engine has been sitting up this past winter on Lopez Island in the San Juan Islands. The mechanic who had serviced the injectors said that during a test spin he may have seen some fuel on the water and suggested that the next place to look was at the diesel injector pump. I am willing to go with his suggestion, but would like to get some additional advice on what else could be the cause. Replacing the injector fuel pump will take one week because he has to ship it off to Bellingham.

The engine runs great, does not burn oil, and according to the mechanic has good compression. Last summer it had the same problem even when the diesel fuel was fresh

Any advice would be sincerely appreciated. I am up here from Galveston, Texas, and only have a 1 1/2 months to enjoy the boat and wish to find a solution soon.

Thanks in advance for any assistance.

Jos

[jpwrist]

Just in case anyone has a similar problem, I went to boatdiesel.com, the Yanmar 6LP site and posted the same question and the response I received is that it is probably the fuel pump. Thus, I am removing it and getting it serviced.

Jos

[rlwpac96]

Did the new fuel pump fix the problem? I've heard the 6LP hates to run at low RPM and this makes it smoke ( low temp keeps from burning the fuel efficiently) but does fine after it heats up again.