I have a 1983 Yanmar 2GM
, and it's been a great engine
up until this season.
Now, I'm getting white smoke (that's never happened before) but also the RPMs will drop off suddenly. We'll be motoring along at full throttle (3000 RPMs under load is where it tops out - I've had the boat for 8 years and that's how it's always been) and then it'll drop a few hundred RPMs all of a sudden. Then, it'll come back to full (or maybe it won't). The last time I had it out, it dropped all the way below 2000RPMs and seemed to be having great difficulty - I didn't think I was going to make it back to the slip - but then it finished the day just fine. And yes, I've changed the fuel
filters and that doesn't seem to make any difference.
What do you think is going on?
I'd appreciate your thoughts. I know that if I have a mechanic
look at it, it'll perform like a champ while he's there and he'll say "I can't find anything wrong with it!"