1999 Force 120hp 25" to 20" conversion

[cassabby]

Just purchased a 1999 Force 120hp outboard with a 25" lower unit. I'm looking for the list for converting it to a 20" by removing the 5" spacer below the drive shaft housing. As I see it based on parts microfiche I will need a compriable spline 20" shaft, a 20" shift shaft, a 20# water inlet tube, standard shorter housing bolts/studs and a gasket set for lower unit. I'm trying to buy the primary parts via ebay and am running into some part# issues. Can any one tell me if an F694128 or 45-F694128 will work for the 1999 20" shaft? Thank you for your response...I'm having a merc marine dealer do the work...I need to aquire the bigger purchase parts. Any help with the parts list would be appreciated. Please no shoot off the hip answers as I am in the process of shopping up hard parts. Thank You! cassabby

 

[Frank Acampora]

Re: 1999 Force 120hp 25" to 20" conversion

I don't know part numbers but you do need to be careful. Sometime in the 90s merc changed the splines in the crankshaft. SO: there are two versions of the short drive shaft out there. One is splined for early Force crankshaft and the other has late Force splines--different tooth count. Suffice to say that if someone is selling a '90, '91, or '92 shaft, it will not fit your engine.

 

[cassabby]

Re: 1999 Force 120hp 25" to 20" conversion

Thanks Frank, If you run into some more info I would be very pleased to here about it.