mercruiser with alpha 1

[renny1]

hi everyone.i have just bought myself a 21ft morebas 7200 to be used for fishing (and hiding from the wife) it is a 1981 model and the engine is original to the boat but i cant find what engine it is. its a mercruiser and has 120hp and i would say 1979-1982 what i need to know is it a 2L or 3L and what sort of rpm should she be at WOT(manual on order) and would she make at least 25knts i have to change the exhaust bellows and new fuel filter and maybe clean the carbs but she runs ok (on muffs) what bad things do i need to check with mercruisers. she has only ever been used in fresh water

 

[bigbob_FTW]

Re: mercruiser with alpha 1

looks like a 2.5L (153CID). I believe WOT rpm is 4300.

 

[renny1]

Re: mercruiser with alpha 1

thanks bigbob gets me a bit closer lol anyone ideas on top speed on a 21ft morebas(not been on water yet)

 

[Fishermark]

Re: mercruiser with alpha 1

A 21 ft boat with a 2.5 liter will probably be lucky to get out of its own way. My dad's old boat is an 18' Sportcraft which originally came with a 3 liter. It ran pretty good. When that engine died he put in a 2.5 liter (the same as yours). It made a noticeable difference.... for the worse. With one person it moved okay, but with more than one it was a real dog.

 

[bigbob_FTW]

Re: mercruiser with alpha 1

I'm lucky, as my boat is only 16'. with a 19P prop I can top out right at 40mph with just me in the boat.