Engine Troubles!

BMW Marine - D12 Diesel Engine

During the deliver of Something Else from Chula Vista to Long Beach California the engine died 15 miles off shore and over 50 miles from our destination. When I bought the boat it had a 10 HP BMW D12 marine diesel engine. Yes, BMW made marine engines for a very brief time. The D12 model has a single cylinder and has some “interesting” design features. However the design flaw of thin casting in the head was the down fall of the D12. They are raw water cooled. That is they circulate sea water in the engine to cool them. Salt water is very corrosive and the cast iron head rusted out. A new head today is made of “unobtainium”. Rich at V12 engineering in Canada bought up all the spare parts in the world and has cornered the market on BMW Marine parts. He sales a usable head on Ebay for $2500. I had a useable head I bought for $200 in my hands in 2011 but I decided to re-engine now instead of later when the replacement head rusted away.

The BMW engine was not the original engine for a GK29. From what I’ve read they came with a 9 hp Peters diesel. But maybe my GK29 wasn’t completely finished at Westerly and it was finished by the original owner?? I read Westerly did home completion on a few boats. BMW Marine was in business from 1977 to 1987. My boat is a 78. I have been unable to find the elusive "build number" so I don't know if it's the 1st boat or the 182th GK29 made between 1977 and 1982.

I bought a 2 cylinder 15 HP Yanmar diesel engine I found on Craigslist. I like Yanmar because the parts are plentiful and Yanmar/John Deere tractors engines have many common parts.  Also the purchase price was in my budget (CHEAP).  The engine was a taken out of a scrapped boat. It didn’t look too bad but I rebuilt it to be sure of its condition.  It is a little tighter fit than the old engine and I had to custom make brackets for the engine mounts for the engine to align on the BMW bed (white fiberglass shell the engine bolts to).

2QM15 Yanmar Diesel Engine