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Problem starting Yanmar 2QM20H and white smoke when running
I'm trying to help my father get our Yanmar 2QM20H to start again. It started with that the tank went empty this spring and then there has been no luck since. The feed pump was changed and that helped us to get it to start 3 times after much labor.
Now after lot of bleeding of air we managed to get it started, just. But have to run for some time with start engine and compression release in before it finally kicked in. Then it ran on low rpm 10 of max 25) on full throttle. After some more bleeding of the return line while running the engine it finally revved up to max rpm. We ran it for some 10 minutes on 70% speed, but all the time we got massive amount of white smoke (not water vapor as it was stinging and smelt smoke). Cooling water comes out ok but there is also diesel coming out of the exhaust as we see a growing diesel shine on the surface of the sea around the boat.
When the engine died due to low speed, we could not start it again.
I'm wondering if it is the injector nozzel that has a problem. They have bee overhauled, but not replaced. I took out the two and one had some brunt residue around the pin sticking out, while the other was just wet.
Could it be the case that the one gets high enough temperature while the other doesn't and that there is unspent fuel?
I just hope it is not the HP pump...
Any hints or tips much appreciated!
PS: There is Tall Ships Race in town these days so we are anxious to get the engine running to go out and look at the marvelous ships.