Can someone explain how my Yanmar 3GM in one boat is rated at 20 HP and in my new to me Hunter 33.5 the Yanmar is rated at 27 HP? They are both 3gm do they have different HP pumps? Or?
Mine is rated at 22.5 hp. That is what the data sheet says that I received when we bought the boat. Further research is needed. Mine has a 72 mm x 72 mm bore x stroke. Someone told me once it has sleeves in the cylinders. Were later models built with out the sleeves? That might account for a hp increase.Can someone explain how my Yanmar 3GM in one boat is rated at 20 HP and in my new to me Hunter 33.5 the Yanmar is rated at 27 HP? They are both 3gm do they have different HP pumps? Or?
Somebody (maybe the great Smokey Yanick?) said " the only way to beat cubic inches is with more cubic inches."The 3 HM is rated for 27 hp continuous, 30 max, one hour. It has a bigger bore/ stroke and displaces 1126 cc versus the GM 879cc. They look identical on the outside.