125 force, any good?

[PIP]

Got access to a 1987, i think, 125 force. Is this any good? How does it compare to 140 crossflow, or an old inline 6 merc performance wise?

Thanks

[capnzee]

125 Force was a Chrysler, which was a West Bend and they didn't change much. I don't think you could compare them to either a V-4 or the inline 6.In the 80's they were heavy engines, didn't have a lot of smack, really, not much of a comparison. If it is running and you are getting it real cheap and you are looking for an engine for a pontoon boat, well then maybe??? The Force was bought out by Mercury as a place to get rid of a lot of their old parts and they did get better into the 90's. I think Merc may have just wanted to get rid of the growing competition and wanted a cheaper engine for their retail line. I'll bet there are a lot of guys with other opinions, this is just mine. I worked for a West Bend dealer in the 50's and we tried racing them with out a lot of luck. The 100 horse was a big disappointment when we put it on a 14 foot hydro. The two cylinders did better, in fact the 40-45 hp became the engine to run in the 36 class. They got well into the 40 mph range on small run-a-bouts. R:)D

[JohnsonM50]

I know little of the 125 but rode spotter for a couple pals water skiing. Their 125 force would smoke my 85 OMC. I thought it pretty good, of course you would expect that from 40 more ponies on a similar boat.

[Fastjeff57]

To their credit, the West Bend/ Chryslers at had a decent reed setup at least! Their huge, external reeds are a vast improvement over Merc's air-strangling arrangement.

Jeff

[PIP]

are they hard to find for this motor? i thinik it needs one or the other. thanks how much?

[capnzee]

Is that a 4 or a 5 cylinder engine. There used to be a 5 cyl parts motor around the corner from me. Rod

[mercguy]

Is that a 4 or a 5 cylinder engine. There used to be a 5 cyl parts motor around the corner from me. Rod

the 120/125 is a 4cyl, the 150 is the 5cyl..............the 125 has a terrible ignition system..........they also eat up motor mounts and the exhaust bellows is often torn......thus causing the motors to "choke out" at low speeds.......

[capnzee]

Will the 5 cylinder fit on your mid-section? I could probably get it reeeeal cheap plus shipping of course.

[wolfgang]

Will the 5 cylinder fit on your mid-section? I could probably get it reeeeal cheap plus shipping of course.
The 5-cyl fits pre- and post "Mercurized" midsections. The post (`96 on) use a special adapter plate, to which fastens a sort of Mercury lower cowling. As you would want to use the narrower 5-cyl. lower cowling and upper fiberglass cover, you have to modify the original 5-cyl lower cowling to accept the four bolts from the special adapter plate. I am busy with that conversion just now, but still envisage sealing problems around the adapter plate. There the Merc has a rubber seal and a U-shaped cover, which hides the tips of the studs on the underside of the block. Can tell you more after this weekend.

[David Mason]

I rebuilt one for a friend this last summer. I have to say, parts are not easy to come by for that thing. Bearings are easy of course, as you can have them made or to spec at any good bearing shop. But pistons... and seals, etc.... were not easy and expensive. Some outfit was selling a rebuild kit, it included needle bearings, rings, pistons, and seals and was around $800.00.

Very easy engine to work on though, wiring was pretty straight forward, and no suprises. Well one suprise, I had never seen a 5cyl before so I thought it was pretty funny.

[Fastjeff57]

For those of you out there who've never seen that 5 banger up close, it has three IDENTICAL carbs. The top and bottom pairs of cylinders breath through one carb a piece, where that lonely center cylinder has a carb all to its own. Somehow that setup actually worked but, when the throttle was whacked open, one suspects the center cylinder was 'helped' up to speed by its four brothers!

Jeff

PS: I have a few of these carbs and a reed assembly or two if anyone needs them. Was going to use them to make an external reeds triple Merc 700. Might yet.

[wolfgang]

I rebuilt one for a friend this last summer. I have to say, parts are not easy to come by for that thing. Bearings are easy of course, as you can have them made or to spec at any good bearing shop. But pistons... and seals, etc.... were not easy and expensive. Some outfit was selling a rebuild kit, it included needle bearings, rings, pistons, and seals and was around $800.00.

Very easy engine to work on though, wiring was pretty straight forward, and no suprises. Well one suprise, I had never seen a 5cyl before so I thought it was pretty funny.

But the sound is beautiful - a bit like a four stroke V10, especially with the lower unit removed. Plus, the 5cyl might be regarded as a collector`s item.
mercruiserparts.com still have most of the spares at reasonable prices, and for the post `96 engines CDI can help with the (Mercury) electronics. Other parts can be gotten off e-bay.
Didn`t make any progress with pulling the 120hp four with adapter housing off the leg this weekend. Discovered two hidden Allen head bolts at the front-difficult to get to.

[wolfgang]

Now I know and would like to advise all mixers and matchers like me:
the post `96 4-cyl Force powerheads coming off the then Mercury (120 to 200hp) tower/gearfoot assy will NOT fit the older Force and Chrysler driveshafts, unless major machine-shop work is done. The Merc driveshaft has a larger dia and a different (coarser) spline. It could only be accommodated with the `96 and later revised (larger dia mains and big ends) 4-cyl crank.

[RForeman]

I raced for Force Outboards several years. Won many races in the F-100 and Mod 110 classes in OPC and placed 2nd at the Nationals in Kankakee in 1988 with a 125 Force.
The 4 cylinder is a cross flow motor and will not turn high RPMs. It will provide very good horse power at 6,500 -7,000 RPM. Carbs and exhaust are key to making the motor run good.
We never had an ignition problem and ran fixed timing.
-Roddy

[wolfgang]

I raced for Force Outboards several years. Won many races in the F-100 and Mod 110 classes in OPC and placed 2nd at the Nationals in Kankakee in 1988 with a 125 Force.
The 4 cylinder is a cross flow motor and will not turn high RPMs. It will provide very good horse power at 6,500 -7,000 RPM. Carbs and exhaust are key to making the motor run good.
We never had an ignition problem and ran fixed timing.
-Roddy
Finally - from the man in the know. Many thanks for your contribution, Roddy. The rev range you are mentioning we would not have dreamed of with the old Chrysler in the late `60s. What flywheel did you use? and what porting would you suggest for 6500 max?
rgds, Wolfgang

[JohnsonM50]

Finally - from the man in the know. Many thanks for your contribution, Roddy. The rev range you are mentioning we would not have dreamed of with the old Chrysler in the late `60s. What flywheel did you use? and what porting would you suggest for 6500 max?
rgds, Wolfgang The RPMs are also dependent on prop choice, weight & drag.

[wolfgang]

The RPMs are also dependent on prop choice, weight & drag.
This venue being BRF, we are talking racing speeds here. NU (1650cc=100ci racing runabout as per UIM), predecessor of ON until the cats came.
rgds, W

[chrysler_joe]

I didn't know west bend made a 100hp outboard Was this a test motor?

[Mark75H]

Not 100hp, 100 cubic inches or less. All of the 4's are less than 100 cubic inches.

[Fastjeff57]

That 5 cylinder had a unique intake arrangement (that apparently worked okay): The top and bottom pair of cylinders breathed through the same carb as the center cylinder did all alone.

Jeff