Compatible drives

[Rranger]

I have a 1993 Force 90 hp I just bought with a boat and when I got it home and dropped the drive oil, about a cup or two of clean water came out and then some nasty looking black oil. The boat hasn’t been in the water since Jan 2017 so I’m assuming my drive and prop shaft bearings are probably not long for use. I flushed with auto tranny fluid left it in over night and drained it. I’ve replaced the impellor and did a vacuum 6 lb. 20 minutes and a pressure test 15 lbs 20 minutes and it held. The unit has a drain, fill and vent plug, I put a oring on one of the plugs that didn’t have one before the tests so I’m assuming that one little oring being missing caused the water problem. Or am I missing something here?
I’m in the hunt for a outdrive or complete 90 hp for parts if possible.
Main question is can someone fill me in on other compatible outdrives off bigger or smaller force engines and other years that would work. Mine is the 1993 Force 90 hp with the two piece drive shaft.

 

[Nordin]

When you vaccum and pressure test did you turn the driveshaft, propshaft and shift the gearcase from forward, reverse and neutral?

If it hold vaccum/pressure for 20 minutes even when you turn/move driveshaft, propshaft and gearshifter then it look like waterproof.

The 2 piece LU came in 1989 I think and in 1995-96 they started to use Mercury LU on Force engines.
Soo a LU from an 90, 120 or 150Hp will fit, BUT there are difference in ratio. Some of them are 1,73:1 and some 2:1.

 

[jerryjerry05]

The GOOD part!!!
The "clean water" and "black oil"
That shows the gears are probably not rusted and probably still usable.

Water settles in the bottom and probably didn't get to the moving parts.

1989 -94 (85 L-drive)90/120/150 all used the same gear housing.
But the gears can be 2 different ratios??Thus the type drive? A B C ?
The housing has a letter stamped on it and it can denote different gears.

Any idea of the model# ?? A B C type?​

You'll need to see a parts diagram or post a pic of the lower unit.​

Check the housing for a model letter.​

 

[Rranger]

When you vaccum and pressure test did you turn the driveshaft, propshaft and shift the gearcase from forward, reverse and neutral?

If it hold vaccum/pressure for 20 minutes even when you turn/move driveshaft, propshaft and gearshifter then it look like waterproof.

The 2 piece LU came in 1989 I think and in 1995-96 they started to use Mercury LU on Force engines.
Soo a LU from an 90, 120 or 150Hp will fit, BUT there are difference in ratio. Some of them are 1,73:1 and some 2:1.

Thank you for taking the time to respond. I did not shift and turn the shaft while testing I will do that, without taking the LU apart is there a way to determine the gear ratio, when i am looking at one to buy? Thanks.

 

[Rranger]

The GOOD part!!!
The "clean water" and "black oil"
That shows the gears are probably not rusted and probably still usable.

Water settles in the bottom and probably didn't get to the moving parts.

1989 -94 (85 L-drive)90/120/150 all used the same gear housing.
But the gears can be 2 different ratios??Thus the type drive? A B C ?
The housing has a letter stamped on it and it can denote different gears.

Any idea of the model# ?? A B C type?​

You'll need to see a parts diagram or post a pic of the lower unit.​

Check the housing for a model letter.​

I hope you are correct about the water level being low enough to not compromise the prop shaft bearings. although I did drive 5 hours home with the engine up and the water slopping around in the drive. But I do have a line on a replacement parts motor and drive, so checking to make sure I get the right one. good to know about the gear ratio, will have to get up to speed on that.

 

[Redbarron%%]

Are you talking about an L drive?
I assume that is the outdrive you are talking about is the L drive.
I have 90 hp Sport Jet that is similar and I bought an unloved boat to get a good engine and drive for spares to keep the Hobie Jet Fisherman alive so I understand.
My advice is to not over think it, change the oil and get it running and enjoy.

 

[Rranger]

My parts guy provided me with this to order future parts. Mine has the anode like the pic of Type C and D will check for the number 4. .

https://shop.seawaymarine.com/OEMpar.../COMMON2944033

 

[Nordin]

Rranger it is really easy to determinate the ratio.
2:1 the flywheel turn 2 revolutions when the prop turn 1 revolution.
1,73 the flywheel turn 1,73 revolution when the prop turn 1 revolution.

 

[jerryjerry05]

IF??? your really worried??????
Take the bearing carrier out and inspect the internals.

The link you posted shows 2 different bearing carriers and the way they're held in.
The one with the 4 screws is the easiest to remove as you probably don't have the
retainer tool to remove the retainer.
Remove the prop and take some close up pics of the prop shaft and carrier.

Once you start taking apart the lower unit, you'll really need a manual.
A factory one is best.
u-tube has a bunch of video's that can help too.

 

[Rranger]

Rranger it is really easy to determinate the ratio.
2:1 the flywheel turn 2 revolutions when the prop turn 1 revolution.
1,73 the flywheel turn 1,73 revolution when the prop turn 1 revolution.

Thanks Nordin appreciate the info.

 

[Rranger]

Got it out a couple times, every thing in the drive sounds and runs smooth so hopefully all good. will run er til she pukes, thanks for the help.

 

[Rranger]

When you vaccum and pressure test did you turn the driveshaft, propshaft and shift the gearcase from forward, reverse and neutral?

If it hold vaccum/pressure for 20 minutes even when you turn/move driveshaft, propshaft and gearshifter then it look like waterproof.

The 2 piece LU came in 1989 I think and in 1995-96 they started to use Mercury LU on Force engines.
Soo a LU from an 90, 120 or 150Hp will fit, BUT there are difference in ratio. Some of them are 1,73:1 and some 2:1.

Nordin if I vacuum and pressure tested the drive without turning the prop and had no loss of air and then tested same and turned the prop and lost air does that isolate the leak to a prop seal or still possibly interior seals or even plug seals? I took on a little water last time out before draining oil and storing it.

 

[Nordin]

As you lost pressure when shift and rotate drive/prop shaft then you have a leak in the shift shaft seal, drive shaft seal or and prop shaft seal.
Try to pressure test with only move shift shaft then turn the flywheel and test.
That is the way to isolate the leak.

 

[jerryjerry05]

Take the drive off.
Spray bottle soap and water(for bubbles)
Drain the oil.
Pressurize to 10-13#
and turn the shafts and spray with the bubble stuff.
Spray at the shift shaft too as you pull it up and down.

 

[Rranger]

I don't ' have time to deal with this leak til spring I'm going away for winter soon. Question is I drained the oil and saw that some water had got in. Am i hurting anything letting the drive sit empty of oil for the winter?

 

[jerryjerry05]

NOT a good idea.!!!! the gears will rust up and the bearings can seize.

 

[Rranger]

Thanks will filler up.

 

[flyingscott]

Replace the washers on the screws.

 

[Rranger]

I filled it up with oil for the winter. I'm heading to a warmer climate without my boat. In the spring I will order a complete set of seals including for the screws and will service and test to find the leak. Thanks for the help