glassdave

iTrader: (1)

there is a marina here that i do some biz with that has a bunch of miscellaneous lower units laying around and i am trying to find a spare for my boat. how do i identify an alpha gen1 with 1:50 ratio? are there #'s to look for? i dont want to end up with a smaller HP series drive by mistake. thanks all.

mine is a 1985 260hp merc alpha gen1

rchevelle71

iTrader: (1)

Gen-I will have a plastic water pump housing, Gen-II has metal, that is the only thing I can think of right now, but I am sure there are more differences. As far as the ratio, you would probably have to spin the shaft, and see if it turns 1.5 or something more or less on the other end????

Iggy

I thought the upper gear case had the reduction ratio gears and not the lower case?

rchevelle71

iTrader: (1)

I am not sure, never dug that deep, but if you are correct, then he is all set, any gen-I will do.

glassdave

iTrader: (1)

iggy i think you are right now that i think about it. i've actually ran this question by the board a few times but my memory sux anymore.

rc- i was thinking that would work to detrmine ratio. thanks for the tip on the plastic housing. that will help.


i just want to make sure if the lower hp units were the same or not. i know they used alphas on smaller 4 and 6 cyl boats. thanks all

happy hours

Alpha has the gear ratio in the upper. All the lower ratios are the same . The guy that said the Gen I hasa plastic water pump housing was correct. The metal one is Gen II.

Mike