Need the facts (From the OMC xperts)

[Charles Salsman]

While Im thinking about it....... I notice that my geasrcase was probably one of the last ones to be made with a straight skeg. Are there any rules of thumb about the length of taper, and the angle?

It appears to me that if I were to change the shape, I should make the bottom edge protrude down the same distance from the center of the propshaft to the cavitation plate (7.5" or so)

I notice that one side of my skeg seems to be flat, and the other is rounded.

I also notice that there is a small ~3/16" hole below the 4 water inlets. There is no mention as to it's purpose in my service manual. Que'st-ce que c'est?

Also, there is a passageway for intake water that leads directly to the exhaust. In this drawing, it shows it. Can someone explain what's happening here?

[Skoontz]

When you say dual rotary, do you mean a spool that both cabnles come off one side and connect from the same side to the motor?

Or does one cable come off each side and connect to the right and left side of the motor? You don't want a dual cable to one side steering set up if you can get the other kind. It's not as stable.

[whaledog]

Trim tab has a cooling water pickup to cool the prop hub in later production engines.

[Charles Salsman]

Hi Skoontz. The steering that I got is Teleflex Dual-Cable No-Feedback Rotary 4.2 "Pro" with tilt helm.

It is a side steering setup, as it is a bassboat. I extended the seat towards the center, but not totally, just about 8 inches closer. I built a new console and moved the steering wheel to the left also. It was very uncomfortable to sit there before I did all that. Anyway, there would be really no way to put in an opposed(?) cable setup.

The "Rack" dual nfb "Pro" kit was about the same cost, but they make you buy the tilt helm separately, so thats why I got the rotary. Im much farther along than when I took this picture, but it shows the console I built using the "hollow foam" trick & epoxy/fiberglass. I then made my first attempt at shooting metalflakes & gelcoat. Now, all the horizontal surfaces are dark(er) blue metalflake and the vertical surfaces inside the boat are white.



This was my old "console", if you want to call it that.




And finally, one more picture that inspires me.... I believe that is Darris Allison driving that beautiful boat, and Im pretty sure that's a 150 Merc. he's using!



Looking at the various models they made (From pictures on the internet) from 1974-198? or so, they changed various features of the transoms each year until 1984 when they came out with an entirely new bass boat.

I may need to add a "channeled air planing apparatus" on the underside of that step, which was something had not yet thought of in '76... but thats a subject for another topic. This one is about waking up this old 135...

Back to the gearcase.... B. Leonard had written a post about these gearcases that said they would blow out at around 55-60 mph. Is it the blunt shape alone the reason for this, or the skeg? Or both?

In other words.... would I be able to put a cone on without a LWP and still be able to keep water pressure? Ive seen some mention of plugging some holes, or making one large opening for the water.

Roughly how many gallons/minute flow through an outboard of this size, at WOT? I have 2 tubes coming off of my impeller. Most just have 1.

[MN1]

Charles,
My brother raced a 1973 135 Johnson in 1974 in the FS class, with duel Ride Guide too. The class specified that the prop shaft had to be 5" below the bottom. He used a Merc 2 blade 28 pitch Elephant Ear prop which was made to fit the OMC. I believe the speed was 70 mph with two people, an (full)18 gal fuel tank and a 90 lb tractor weight glassed in.
We had Bill Richter Sr. mod the motor for us. I don't know what he did but it really helped. His son is on this site with the screen name (brichter).
Bill Gore has done lots of work to OMC V4 motors too. He's had many National Championships won with motors he's built in the Formula 100 class. And I'm sure more in other classes too.
He's an old time photo of my brother.
Mark Nelson

[Charles Salsman]

Ok, a middle of the night idea:

Is there any reason that I could not take a 1976-1978 V6 gear housing and stuff the internals of my gearcase inside, and bolt it up to my 135? From this, I would gain a more efficient nose, and the improved (and patented) skeg.

It looks like it would.... check this out also:

"Both the 400 and 800 series gearcases evolved from the Johnson/Evinrude outboard line (a division of OMC). The 4-cylinder/400 gearcase is similar to the V4 outboard gearcase and the V6/V8/800 series gearcase is similar to the V6 outboard gearcase. Other than the addition of a water pump, different drive shaft and shift mechanisms the stringer and Cobra gearcases will interchange with some of the outboard gearcases!


http://www.glmmarine.com/30yearsomc.html

Im not trying to reinvent the wheel here. But all of the discussions Ive seen about using a 135 powerhead on a later model mid/lower always look at the 140. But the 150 is a V6, and the 135 used a big FAT V6 housing.

Ok, shoot me down Bill.

Good night.

[Skoontz]

The 135 used a club footed version of what the 99.6 cubic inch 140 had. The 99.6 cube 140 had better hydrodynamics than the 135. That was the years of '78 through '84 give or take. When the 122 cubic inch looper V-4 140 came out, it was basically a V-6 with two jugs cut off. All the big V-6 stuff which slowed it down tremendously and made it heavy. That engine ran the fat lower unit the V-6 had.

[Bill Gohr]

OK, You've been shot...............why would you want a "fatter" gearcase? We always try to use smaller ones, what are "we" nuts. Yes you are reinventing the wheel. Send your gearcase to someone who puts nosecones on and they will fit one to it, call it done, your parts will not fit in a V6, or a later gearcase, if you're going to do all this modding, why don't you just get a later engine??? Or put your powerhead on a later center and lower???? There are better things to think about in bed at night.................

[Bill Gohr]

And, the hole below the water pick ups is a drain, and the water that is blown in the exhaust is to cool the prop hub............

[Charles Salsman]

I was thinking this thing has the fat gearcase. It looks like a freakin' blimp!

And earlier in the evening I had seen a newer style gear housing on Ebay for sale for $50. and it looked like it would bolt up perfcectly. It was just a question in my mind. That answers that!

Actually the dogs barking next door woke me up. Then I started thinking about my gearcase.