Bukh DV36 is one of the most common lifeboat engines, it has counterbalancers and though it’s 3cylinder it runs smooth.
It was commonly fitted to yachts in the 80s and is a great engine, the biggest flaw is they weigh about 360kg whereas a modern equivalent is around 170kg. Also parts are expensive.
I have one in my boat, 4700hrs, raw water cooled and has never been out of the boat in 43years.
The Yanmar ones on ebay are typically from ship scrapping facilities in India. These lifeboat engines have a sort of "hard/easy" life. Easy in that very low hours because they seldom run more than a few hours every 6 months during lifeboat drill. But do you think the ship's crew changes the oil more than a few times over 20 years? Probably not. So....pays your money and takes your chances.
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