OK this is my first post. I just picked up a 1989 cruiser in really great shape. I am super excited about it. Great for exploring SEAK with the family. a big step up from my 17' westcoaster. It came with a 92 Yamaha 115 v4 which runs great ( i hit 35 mph at ~ 5200 rpm and it was still not WOT!!!!!!) but lacks the great MPG that CD are know for and i have to mix gas. I have not taking it out to far yet but the previous owner indicated that he got 2.25 to 3 mpg. I have a line on good deal on mid 2000 Honda 115. I think this OB would significantly improve my MPG and range but it is the heaviest of the 115(~500#). Can my 89 cruiser handle that much weight on the transom? can I move weight forward ( batteries and saddle tanks) to compensate for all that weight back there. If not what are some ways to improve efficiency with the Yamaha. right now it is running an aluminum 13.25 x17 prop. I was thinking of a ss 13.25 by 19? thanks in advance for your input.