What counter rotating gear cases can fit the Mercury 150 4 strokes

[Mini Max]

I am designing a 2021 Switzer wing clone for Mercury 150 4 strokes.

The problem is, 20 " legs are only RH rotation and 2;1 gears. You have to buy a matching 25" LH gear case and change out the drive shaft to get 20"

At the expected speeds I would need 34" pitch props with the 2:1 ratio and modify the foot.

I desire 1.75 or 1.6 ratio. Will the sportmaster bolt on?

While I am wishing what about a 15" tower?

[PanRonnie]

I was playing with the same idea after reading the articles of jared of wave to wave
I am pretty sure the 3 liter case will fit if you can modify the drive shaft to the 20 splines of the 150 fourstroke
Another option would be the sei stub gearcase
These come in a 1.62 gear option and have the bullet water pickup
Get a 150 fourstroke drive shaft and make a coupling

[25two.stroke]

If you were gonna mod a merc case (like a nose cone) I would start with the SeaPro gearcase, stronger and you get to start with a 1.92 ratio, which is closer to what you want.

[FUJIMO]

I am designing a 2021 Switzer wing clone for Mercury 150 4 strokes.



While I am wishing what about a 15" tower?
...18 or 20 foot switzer clone?... or? ...yeah, really...a couple 15" shaft engines would be the bomb, with speedmasters. but also wondering if a pair of 15" left & right cle's would bolt up?

[25two.stroke]

CLEs or SSMs would fit if someone was making a custom mid/adapter, but I think the question was about what would match up to the 150fs bolt pattern as it is.

And it does appear that the 3.0 2 stroke cases have the exact same bolt pattern. They all use the same water pump and housing. The shift shaft looks like it is in the same place and it may be the same height. I have a 150 but its 20" so I couldn't take a 3.0 sporty and bolt it up because the driveshaft would hit. If I had a 25" I could take a 20" 2stroke case and bolt it up and see if everything aligns but the driveshaft. I may pull the shaft out of a 3.0 sporty or TQ and see if it bolts up. If it does, then all that would be required to get the correct gear ratio and shaft length is swapping the 4s shafts into 2 3.0 Sportmasters.

[Mini Max]

I was playing with the same idea after reading the articles of jared of wave to wave
I am pretty sure the 3 liter case will fit if you can modify the drive shaft to the 20 splines of the 150 fourstroke
Another option would be the sei stub gearcase
These come in a 1.62 gear option and have the bullet water pickup
Get a 150 fourstroke drive shaft and make a coupling

All good suggestion as is the Sea pro. I can get the standard 150 mercury 4S gear case which is 2:00 ratio in 20" RH and 25" LH. Swap 25" drive shaft for 20".

I am contemplating making a composite 15" leg if it turns out I have to jump through a lot of hoops. The sport master gear cases are $6-7,500 each which when added to the engine cost makes a very costly 150.

[25two.stroke]

Yeah. To be honest I don't know how much gain you would see with the sporty. Is there a reason you need that ratio? I know you are considering the max pm of those engines along with your prop setup, but has anyone adjusted the ECUs on the 150s like Nizpro is doing for the yamahas? Is it possibly that you could just cone a seapro case and prop it right? I assume you would start with the ProXS fourstroke 150 so you get that extra rpm in the computer? That coupled with the 1.92 case of the sea pro ought to make a nice combo.

I wonder if the gears fit from the 3.0 sporty to the 4s/sea pro case? I know the 3.0 sporties come in the fat propshaft too, and none of the 150 4s cases ave that option.

If you cut your mid down to 15" would the oil pan/fuel cell get in the way? I know there are people cutting 4strokes down, so what do they do about that? Do they relocate the fuel cell and cut the oil pan?

[FUJIMO]

...too much bs. track down a couple 15'' counter rotated 2-strokes with the gearcases that a switzer has to have to get water pressure, use them, and then get all your money back later, that you paid for them... zero headaches.

[Mini Max]

...too much bs. track down a couple 15'' counter rotated 2-strokes with the gearcases that a switzer has to have to get water pressure, use them, and then get all your money back later, that you paid for them... zero headaches.

Agreed but I have not found any. Been looking for a pair of 15” 200 xs ROS with no success. By the the way, was Jane your X?

[FUJIMO]

Agreed but I have not found any. Been looking for a pair of 15” 200 xs ROS with no success. By the the way, was Jane your X?
...too much h.p. for a 20 foot wing. for that power, with the weight you build things, your wing can be 35 feet. no on jane. nice try though jim.:cheers:

[PanRonnie]

Agreed but I have not found any. Been looking for a pair of 15” 200 xs ROS with no success. By the the way, was Jane your X?

Doing things not because they are easy but because they are hard is much more rewarding! :D

[Mini Max]

It's planned to be 30'. My daughter wants to ride too. My Wife not so much. When I was a kid mowing grass in Columbus Ohio I heard a wail coming from the river 2 1/2 miles away. I shoved the mower into the bushes and ran and jumped on my bike to ride to the Scioto River. I climbed down to to the rivers edge on the rocks of the Griggs Reservoir Dam just below the turn pin.

I watched a Black Mercury Stacker fly directly at me at face level and then turn (barely) a hundred feet away.

It imprinted my brain and I wanted that to be me for my whole life.

[FUJIMO]

...a lite 30 footer? excellent. i would dare to say you could use the 20'' 4-strokes as-is then...always counter-rotated, with normal gearcases, spinning as large a diameter props as you could find, with your only hurdle being where your going to get water... deeper than usual, maybe stationary, maybe retractable, remote pickups or something...i don't know... thought u were a michigan guy/kid.

[Mini Max]

A 1.25 overdrive gear case made for a 150 mph OMC water speed record boat.

This is a nice place to get water. follow the finger.

[Mini Max]

533009533010

The Wing project got shelved. I could not get engines for 2 1/2 years with so much stimulus money out there Mercury only supplied their "A" customers. Having "only" 12 engines on order I was not "worthy" Since I wanted to race, Stock outboard was happy to have me. Great folks, always generous with their mentoring and help. I settled into BSR and DSR Marathon. My D has a seat as kneeling was not an option for the duration of a Marathon.

[FUJIMO]

...cool. corecell?...https://www.screamandfly.com/attachment.php?attachmentid=533009&d=1716894165

[FUJIMO]

https://www.screamandfly.com/attachment.php?attachmentid=533010&d=1716894221

[Mini Max]

...cool. corecell?...

Divinycel. I had built 500 "Egret" flats boats starting in 1993. We ended with Corecel bottoms and a rigid PVC in the deck for its better thermal properties in the Florida sun. After 45 years of composite boat building I have my own laminate design program. TLAB. That Looks About Right.

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