Can i put a 120HP Force powerhead on a 1991 90HP Force leg?

criddy72

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Joined
Jan 23, 2011
Messages
14
Looking for some more power without paying an absolute fortune. Can i install a 120HP power head on a 90HP leg? Obviously i would have to change the prop up but unsure if coupling, mounts, wiring, and gearbox could take it?

If so does anyone have one for sale?:)
 

Frank Acampora

Supreme Mariner
Joined
Jan 19, 2007
Messages
12,004
Re: Can i put a 120HP Force powerhead on a 1991 90HP Force leg?

Depends upon the year of the powerhead.Up untill 94, they all were the same and used all the same components with the exception of the three cylinder trigger for the 90. SO if you are using an early Force powerhead, uyes, they are swappable. The 90 lower unit will provide more acceleration than the 120 lower and that includes going up 2 pitches in prop. I.E. If you are now using a 13 X 17 prop you will need to go up to a 13 X 19.

94 and later used Mercury control cables and I am not sure: The block itself will bolt up to the leg but the linkages may be different. They may also have changed the splines in the crankshaft.

Where are you located?
 

criddy72

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Jan 23, 2011
Messages
14
Re: Can i put a 120HP Force powerhead on a 1991 90HP Force leg?

Hi Frank,
Thanks for the reply, i just found it today doing another post regarding this similar question using another engine. I am sorry as i didnt realize anyone replied as i never received an email notification. I have actually been given by a friend a 125HP Force which i presume is roughly a 1988 model by the age of his boat. It was in reasonable shape (i have posted pics of it on my other post). Would this be better suited to bolt onto my 1991 90HP lower unit? Maybe i should just scrap both and buy a 1996 120HP Force i found online which he is asking $2K for? When did they change to 120HP from 125HP?

Thanks again
 

criddy72

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Joined
Jan 23, 2011
Messages
14
Re: Can i put a 120HP Force powerhead on a 1991 90HP Force leg?

Sorry, i am located in Deep Creek Lake MD but work in Pittsburgh during the week.
 

roscoe

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Joined
Oct 30, 2002
Messages
21,657
Re: Can i put a 120HP Force powerhead on a 1991 90HP Force leg?

last year for the 125 was 1989

120 came out in 1990
 
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