First visit to this forum...need part # help for Force 120 hp lower unit seal...

Hello forum members. I thank you in advance for any help you provide . I have been unsuccessful in my search for the shift rod bellows type seal for my Force lower unit. It may be a 125 or a 120 lower unit. The intake for cooling is inline with the propeller center line. Please help me ! I need to get my boat , "Breaking Wind" , 1990 Bayliner Capri Cuddy, back on the water ! I am in the middle of a power head swap and after removing the lower unit ( drive shaft came up and out with the power head ....yeah , that was fun) ...... , I discovered that the shift rod bellows seal had separated .

How in the wide wide world of sports, did this lower unit end up on the bottom of an outboard? I thought that there was a 15 vs. 13 spline issue with the drive shafts??

I think the 15 / 13 spline thing is with the Sportjet powerhead compared to a regular outboard.

Some pics of the unit?
Pics of what you need?
Serial #s Model#s?

Here is a pic of the bellows shift rod seal. Mine is completely separated at the same rib.
My engine is a mix of 1990 120, and what I believe was a late 1980's 125. I do not know the model , or year. Serial numbers faded away about a decade ago. It is either a 125 or a 120 lower unit. The water intake is inline with the propeller center line.
I have learned that this particular bellows seal and water pump was only used for two consecutive years. I sure would like to know what those two years were !
I am currently installing a powerhead from a 1986 125, onto the leg of a 125 that I have no idea what year it is, and I can't remember if the lower unit I ended up installing several years ago , came from the original 1990 120.... it ain't easy be me.... So far , the powerhead replacement is going smoothly.
The cause of the powerhead swap , was pistonitus . This condition was caused by a broken ring and resulted in a grievously scored cylinder wall and serious damage to the exhaust port of cylinder #2. I have three pistons and a crankshaft for sale...!

They started the bellows mid year 1989.and stopped it in 1990 mid year.
Looks like Gregsmere had the post you need.

Jerryjerry05 said:

They started the bellows mid year 1989.and stopped it in 1990 mid year.
Looks like Gregsmere had the post you need.

Click to expand...

Thank you Jerry for all of your help. That info also tells me that the outboard I have it mounted on may be older than 1989. I wish they would have stamped the serial # into the block. I am installing a 1986 125 powerhead on that leg.....just to make things even more confusing..lol. Is there any other way to determine year of a Force ? The outboard in question had the older cowling decals that were used after they went from white to the dark blue. The decal said 125. It was completely different than the 1990 120 that was on this boat when the original owner bought it brand new. He gifted the boat to me about six years ago. The boat was a mess. The engine was toast as well.
If I have found the correct Franz's Marine , I will not be able to call him until tomorrow, Tues. They are only available Tue-Fri. I will see what the price is. I do have access to a machine shop at work...just in case !

They did mark the blocks and the mid sections.
The drives too.
Just gotta know where to look.
Under the power packs is a foundry stamp.
In the center of the stamp is the year.
Same with the mid section. Under the rear cover.

The White paint stopped in 87.
The Blue was used till 99 when they stopped making them.
The main difference was in 92? when they started using Mercury electronics.

The difference in the 85/90 or the 120/125 is the way they rated HP.
The rated it at the prop for the 120 and at the head for the 125.(I think)
The motor used a BUNCH of the same parts and the only real difference is they made small changes you can't really see.
Later years the piston size changed and the stroke did too.

Good luck with Franz.

Thanks again Jerry. So far , the transplant has gone smoothly...other than the shift rod bellows seal. I did have one problem while installing the components that live under the flywheel. I had to swap the plate that has the top crankshaft seal. What bolts down to it was just a bit larger in diameter. Not too difficult. The carbs ( from the 1990) are mounted to the reed cover plates and the reeds from the yet to be determined engine, and now installed on the 1986 block. Shifter and throttle cables installed. Power cables and wiring harness pulled in and mostly connected. Starter , fuel pump, powerpack and plugs remain to be installed. I plan on replacing all fuel lines as well. I also took the time to clean and paint the lower cowling and leg cover. While I was at it, and had the time.....I also removed all of the decals from the engine cover. No easy task. Needs sanding and paint. Labor of love....