Bad fuel is a possibility, the new winter storage stablizer is an unknown. Water in the fuel is also a possibility as there is no water/fuel separator in the system. The mechanic mentioned that an occasional puff of white vapor comes out of the exhaust which he says is a sign of water. Injectors , since the are original 1985 parts, there is no hour meter to determine use, might be a possibility. The deco pression levers are certainly a possibility as I tripped them both into decompression position. I don't know how they work on a Yanmar, on the BMW I believe the lever opened one of the valves partially. The last two choices I don't want to think about.

Yes, there is a fuel sending opening on the tank, difficult to get to, however not impossible as I replaced the sending unit when we bought the boat. I would think that looking in the fuel filter bowl would be my first choice for water, however I'm not the mechanic and I no longer have access to the boat. The mechanic never called me yesterday either.

Thanks for the thoughts, I have my fingers crossed this does not require too many boat units to take care of.