Hello all,I have had a white smoke issue that was not solved last year before I laid my boat up. I'm hoping to get some fresh input.The boat is a 1989 Hunter 30G with a Yanmar 2gm20f. The engine has 650 hours of use. Upon start up I blow large amounts of white smoke. This is indeed smoke and not steam. The smoke lingers, does not dissapate quickly, smells heavily of diesel and leaves a sheen on the water. After warm up the smoke is reduced at idle but anything over idle produces increasing amounts of smoke.My "mechanic" claims that he has had the injectors and compression tested but is vague about where they were tested or any specifics about the results which causes me to question if the work was ever done. I read this in the archive: "You can tell which cylinder is firing by flipping each cylinder compression lever - if no change... that is the one not firing... the other one will kill the engine since it is firing only on 1... fyi, these compression levers are great to know about ... if you ever run your house bank down too low to turn the engine over.... you can open up these levers and there will probably be enough juice to spin the engine ... while spinning at a high rpm close one lever and that cylinder can fire and then you close the second one and your are good to go...."Is it possible that my engine is only firing on one cylinder and expelling raw unburnt fuel as a result? If so, is this method an acceptable method of finding out? As always, thanks in advance for any help.Tim