75hp mercury clam shell motors

[nugent]

been a while since worked on such an old engine or remember much about them,

are these fairly releiable?

if i remenber correctly old hp out puts are vague most likely closer to 60hp with age and wear, or am i wrong on this?

can these be upped to 90hp?

sorry for all the questions but i am in the dark with these 3 cylinder lumps,,,

cheers nuge

[Pikey Dave]

AFAIK hp used to be measured at the flywheel which resulted in less hp at the prop. It's now measured at the prop which gives a more realistic indication. That's about as much as I know.

[nugent]

i thought it was soem thing like that, cheers Dave,

[Jonny H]

Mercury changed over to prop rated horsepower in 1984 which was the brown band onwards

http://www.cmba-uk.com/forum/downloa...3065&mode=view

[Turbodiesel]

Brilliant engine!. You can bolt on a set of 90hp carbs, change the max timing and away you go. Clamshell engines are 1100cc where as the newer bucket cowl types are 1300cc. We always measure the hp from the prop (we measure it in PSI actually and convert it) a well set up one will usually be over 75hp.