engines?

[ken]

I'm trying to find out when and at what HP yamar goes to two or more cylinders I have owned a boat with a single cyl an if the noise didn"t get you then the vibrations would the thing never failed to start but you could mix drinks without a blender, also did they put a multi in anything 27 or up to thirty feet in the 80's

 

[Steve O.]

GM series

1GM = 1 cylinder2GM20 = 2 cylinders, 18 hp3GM30 = 3 cylinders, 27 hp

 

[Terry Cox]

H28 HAS A 2GM

Hi Ken, my 1989 H28 had an 18 HP two cylinder we called thumper. She actually ran pretty smoothly and was ample power for the boat.Terry