1994 90 force super jet

[Buffers]

I bought a 1994 donzi jet boat with a 90 horse force motor, I thought it was a mercury because of the owners manual said mercury. Went to get parts at the Mercury dealer, they told me it was a force motor and that is what they used in the donzi jet boats. Now to find out the motor is not good, and I need to replace the power head.
My question is......
1. I am having a hard time finding a 90hp force power head, plenty of 1980" 85hp and plenty of 1990's 120hp but not 90 horse powerheads
Will any of these 1980's 85hp or 1990's 120hp force powerheads have the same bolt pattern to bolt back on to the jet.?

I am looking at a1996 120 force outboard, someone told me I could remove the power head and use that because it has the same bolt pattern. The 120 is a 4 cylinder and the 90 is a three cylinder, seems it would be bigger
I am also looking at an 1988 85 horse motor and would like to know if that would be compatible ?

 

[kbh121956]

Buffers, I would check your post tomorrow morning before buying any of those power heads. I'm not sure! Jerryjerry05 and Nordin would most likely know.

 

[Buffers]

Thank you.
I will see if I can get in touch with them

 

[Buffers]

just joined,
how can I find a member to ask a question

 

[kbh121956]

They will answer your post. Nordin lives overseas and most likely will answer late tonight. Jerry only answers in the early mornings. There are many others on here that may also answer you post. Give it time, it's the weekend.

 

[Buffers]

Great...
I did figure out how to find a member
Thanks again

 

[jerryjerry05]

The 96 120 should swap.
You need to find out the model and serial#

 

[Buffers]

Thanks
Jeryjerry05
After I get the serial # and model, how do I know if they are compatible?

 

[Nordin]

Sorry but I am not so familier with the sport jets.
They are not so common here in Sweden.

I know that if the block is the Chrysler/Force (basically from early 70.es) the 3 and 4 cyl. will swap as the bolt pattern is the same.

Do not know if the exhaust cover plate is like the L- drive, but if, then that can be hard to find as part.
I recommend you to listen to jerryjerry, pnwboat. Think they knows more then me.

 

[Redbarron%%]

The Mercury Sport Jets use the Force power heads but the crankshafts are different from the outboards.
You need at least the proper crank in any engine you want to use.
The 90 and 120 can be interchanged, but the gearing in the drive is different with the 90 1.4:1 and the 120 1:1
What is the problem with your engine?
Perhaps it is easier and cheaper to fx your problem rather than start swapping engines?

 

[jerryjerry05]

Thanks
Jeryjerry05
After I get the serial # and model, how do I know if they are compatible?

After you post it?? Post pics of the motor, flywheel and exhaust any where the camera can reach.
I'll try to figure out what you need.
More than likely you'll need a motor from a jet.