Since your engine worked before I am going to make a guess here and say that
the fuel timing is off. There is a shim pack that goes under the injector
pump to time when the fuel enters the engine. Shimmed to high and the fuel
enters later and you get less power. Shimmed to little and the fuel enters
to early and you get problems.


"Ron" wrote in message
...
I own a 34' sailboat that has a 1985 Yanmar 3GM30F that needs repaired.
Can't get the rpms out of it that I had in the past plus I am blowing some
black smoke and while in the slip if I give it hard throttle I can see
black
floating on the water. This all occurred after the injector pump was
replaced and adjusted by a yard mechanic. My max rpm's in the past was
3200 -3300 which could be more but is limited by the throttle hitting my
steering pedestal guard. Right now I am getting just 2800 rpms max.

After the suggestion from the mechanic I replaced the old fuel with new
fuel and filters and some hoses were replaced. Fuel line is clean. Fuel
tank pickup is clean and not clogged, tank is clean. I am tired of
playing
with the problem. It has been almost 2 months since I have been on the
water. I am looking for recommendations on a good marina for repairs
somewhere from Annapolis North to Pooles Island.

Thanks