15hp race motors please teach me.

[Glenno]

Hi there,
I am very interested in learning all about the 15hp omc race motors.
I live in Australia and have lived race boats for a while.

1) What year models of Johnson- Evinrude 15hp motors are suited?
2) I have a 1989 model (picture below) but it seems to have an extra exhaust bulge just under the hood clip compared to the other race 15hp ones I have seen online.
3) there is no power pack on the side of the head like the normal 15hp omc, it's under the flywheel, I assume this can be changed back to a standard pulse coil an cd2 pack?
4) I would really like to get a race lower unit but don't know where to start looking.
Please teach me, I'm ready to learn!
Cheers,
Glenno

[Glenno]

Anyone?

[25XS]

The Johnson or Evinrude Model 15SS racing gearcase & adapter plate will fit on your engine... It WILL NOT work if you have a heavy boat. It's designed for a 100 lb racing boat with a 100 lb driver.

You can google 15SS racing gearcase and follow tons of links to information. www.RacingOutboards.com manufactures them now, but they are intended to adapt to a Mercury 15hp two stroke engine now.

Give it some time (patience) here. Many visitors to this website only show up once a week at most, but you have tapped into a goldmine of information here.

Tom

[Powerabout]

they are a great engine
There are some threads somewhere of modding the engine

[champ20B]

These are awesome engines in a race set-up. They are suitable for drivers up to 160lbs in competition. These are a 50-55+ mph ride. If you are between 160-200 lbs in body weight though, it is still a fast ride just for fun. You need to check out the Sorensen race boat kits and plans for any A/B class hydro or marathon style runabouts he offers if you plan to convert your 15 into a racer. You will just need a racing foot and a steering bar. You also will need to lock your ignition in place and just go to a carburetor throttle only, like most stock racers are. Get rid of the tiller. You will need a correct propeller and run it about an inch deep (center of prop shaft to bottom hull line).

[Glenno]

Thanks guys,
Wow 45kg boat , I can do the boat at 45kgs.
I am 74kgs. Are the normal drivers of these boats all kids or do some adults drive too?
Where would I find a race lower unit?
How does the drive shaft adapt?
Is there a water pump or is it just pressure fed?
So many questions.
Cheers,
Glenno

[champ20B]

Thanks guys,
Wow 45kg boat and 45kg driver, I can do the boat at 45kgs but I will be hard pressed to get my wieght down to 45kgs.
I am 75kgs. Are the normal drivers of these boats all kids or do some adults drive too?
So many questions.
Cheers,
Glenno

Your weight is just right at maximum for competition. These engines are good for drivers up to 160 lbs. You are at 165 (75kg) so that is o.k....
Someone said 100lb boats and 100lb drivers but that aint right, and yes, grown men race these engines. A middle weight or light-heavy weight boxer can run one of these 15 racers successfully, and they aren't junior size folks by no means.

[Glenno]

Sweet,
Just wondering what the extra exhaust bulge under the hood clip is as I don't see it on any of the a motors on the web?
Also do I need to change the cd pack under the flywheel back to the standard pulser coil and cd2 pack on the side of the head?
Does anyone have a good second hand lower unit for sale?
Cheers,
Glenno

[sharpeye Mike]

Here is a link for parts on these little motors plus the 45 SST and the 60 SST
http://www.seawaymarine.com/p/SST-Race-Parts-2040

This should help you.

[Glenno]

Thanks heaps I will chase it up.
Out of interest has anyone tried the late model 15hp carb on there race 15? I know it would be illegal to race though. I tried one on my 15hp today and seemed to have a lot more hole shot and a little more top end.

Check out a 15hp I modded a while ago.

[Powerabout]

how did it go?

[Glenno]

It goes hard!
It uses heaps of fuel and is fairly loud.
Believe it or not I have never tried a true race prop on it as I know the ratio in the shifting case is terrible.
I put a 12 pitch stainless with cup of a 25hp on it, spins it up no probs fully submerged. If I ever have a chopper or cleaver around 16p I will wack it on for sure.
I modded that motor because it was free and I have lots of 9.9 - 15 omc parts and I want to learn what works and what doesn't.

[DeanFHobart]

Thanks guys,
Wow 45kg boat , I can do the boat at 45kgs.
I am 74kgs. Are the normal drivers of these boats all kids or do some adults drive too?
Where would I find a race lower unit?
How does the drive shaft adapt?
Is there a water pump or is it just pressure fed?
So many questions.
Cheers,
Glenno

You can google 15SS racing gearcase and follow tons of links to information. www.RacingOutboards.com manufactures them now.

There is a water pump.

Best of luck.