59 fat fifty VS 75hp of same vintage

[yellowpete379]

Can anybody tell me what the main differances are between my 59 fat 50 and a 60 75hp? Is it like the smaller ones and its just a exhaust cone and carb swap?? or a totally different powerhead? Any way to get more power out of it? It runs great but would like more. its on a 75 glastron 15.5 ft trihull and moves it ok but need more for skiing/tubing.

 

[jimmbo]

Re: 59 fat fifty VS 75hp of same vintage

50hp @4000rpm 70.7 cubic inches


75hp @4500rpm 89.5 cubic inches

 

[F_R]

Re: 59 fat fifty VS 75hp of same vintage

What jimmbo is saying is that the 75 has considerably bigger pistons. And no, you can't bore your 50 out big enough to put 75 pistons in it.

The other big difference is that the 75 has a much slimmer lower unit gearcase, meaning less underwater drag. On the flip side of the coin is the 50 with that big club of a gearcase and prop will shove a heavy load better than the 75.