I won this power head [long block] in a British auction. It is 50 hp, 3 cylinders ,but, it is not 43 cubic inches like the normal 40 and 50 horsepower Yamahas we see over here. It has a serial number 100189 on the block. It looks a lot like a 70 6H3 or 6H1 block. The papers I got with it say it had a 14:24 gear case, a 11 3/8 x 12 pitch prop, 4500 to 5500 rpm operating range and a compression of 6.30. The documents look totally Yamaha. I am at a loss with the 62F code. It doesn't match the normal Yamaha outboard codes. They go "number”,” letter", "number" [example 6H3] This motor is 62F! Anyone know what I have here?