1994 Evinrude 120 hp looking to modify midsection/lower unit

k9hunter

Seaman Apprentice
Joined
Jul 23, 2009
Messages
36
I have a 1994 Evinrude 120hp which has been mounted to a 18' Wellcraft center console with a 2' extended transom. Had several electrical and fuel delivery issues, but now are all resolved / repaired. Motor is now running excellent but mid-section / shaft length is too short for boat it is mounted to. On plane lower unit sits too high in water and has a tendancy to cavitate heavily and exsessively. Only way to stop cavitation is to slow down and / or trim motor down as low as possible, which results in motor basically pushing bow down, reducing rpm's and is basically "under" the boat. Motor is mounted as low as possible on transom and on initial take off, powerhead cover goes under water. From all my calculations, need a 25" shaft as apposed to the 20" on motor now to raise power head some and lower foot eliminating both "issues". My question, what mid-section / lower units will work with exsisting power head? Yr? make? model? I am hoping to find a blown motor with 25" shaft I can do a swap with. Thanks.
 

jonesg

Admiral
Joined
Feb 22, 2008
Messages
7,174
Re: 1994 Evinrude 120 hp looking to modify midsection/lower unit

See the top secret file at the top of the forum.
Theres an interchange list showing which yrs fit what.
Thanks to Tashasdaddy.
 

k9hunter

Seaman Apprentice
Joined
Jul 23, 2009
Messages
36
Re: 1994 Evinrude 120 hp looking to modify midsection/lower unit

Thank you Tashasdaddy, lots of useful info there.
Top Secret Chart states:
85-140.............(crossflow 13 spline prop shaft).............1978-1991
88-140.............(crossflow 13 spline prop shaft)..............1992-1998
Found a mid 80's on ebay, seller not sure of model # or yr but claims it will work on my 94. In the pictures it looks identical (power head, mid section, lower unit) but hate to spend the money if it wont fit. Pictures dont tell it all. Based on the table (above) from the lower unit compatability from top secret files, 80's wont work on my 94. Is this accurate?
 

wilde1j

Vice Admiral
Joined
Apr 15, 2002
Messages
5,964
Re: 1994 Evinrude 120 hp looking to modify midsection/lower unit

xxxx
 
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