1967 650 4 cyl to 50 hp case?

[e4light]

hello all ive been keeping my boat resto a surprise and if I can get all my ducks in a row here it wont be long till I start my thread about it all. Anyways I have a question my boat requires a short shaft motor and I just painted my boat and put a new transom in so now that im getting ready for a motor I have a 1967 merc thunderbolt 650 four. and I am wondering if it is possible to put the 65 hp powerhead on a short shaft 50 hp case and use all the 50 hp stuff to convert it to a short shaft outboard.

 

[matt167]

Re: 1967 650 4 cyl to 50 hp case?

Unfortunately no, the 50hp 4cyls use a smaller gear case. The 650 will swap with the larger 4cyls and the later 6 cylinders ( '65+ IIRC ), but the gear ratio is only right with the 4cyls at 2.3:1. The 6cyl is 2:1 I think.