3 cyl exhaust

[evilrude 1]

Here's some pictures of my little 70








I removed the inner liner of the midsection and added the exhaust snout (there are 1/2 inch holes drilled through the mid inside the exhaust snout)
It really isn't too loud-but thats all relative to each individual-I think it sounds perfect. Just search U-TUBE with "critchfield" and you will see and HEAR a pile of em with omc power.
Coming down off plane it really crackles and pops and at idle it really sounds like a 2-stroke sled
I have also port matched every thing from carbs to block half`s and spent hours porting the reed cages.
But this is not a ski machine its a fast little speed boat. I think if your just going skiing you should stay away from intake/exhaust porting as there is not much bottom end to begin with on a 49 cid) maybe go with the 56cid.

[phillnjack]

ive been looking at this over and over again, and I cannot understand why the gearbox has been drilled in the exhaust area !!!
why do this when you have already taken out the can and put on a snout and drilled through the mid section ?
surely you get enough exhaust out the mid section with the snout or is there only a couple of holes that's not enough or is it all just for show realy /
dont get me wrong I think it looks great with the snout, but cant see the need for the gearcase to be drilled.

[evilrude 1]

yup - all for show ! I put my spare keys in there.

By the way I spin a 23p srx over 7000. gps at around 70 mph. Thats all for show too.

[FMP]

HA! The bling holes!

[ACAMS]

Would you give detail on this water intake mod?

Here's some pictures of my little 70

[evilrude 1]

Sure I'll give details

The inner exhaust liner is removed by cutting it away (you'll know what I mean when you start tearing into it)
and I epoxied up the water ports that lead to the mid (on the adapter plate) and drilled/tapped 2 holes in the back of the adapter to which I then used fittings and plastic line (all avail from any truck dealer) to dump the cooling water out.
This is called dry stacking. (the engine really crackles from this mod)
I have also recently add transom mounted water p/u and closed off the l/u water inlets.
The only reason for doing this is because the hull does not have a PAD and I was getting low water psi.

Hope this helps

[FMP]

How many c.i. with this triple?

[evilrude 1]

Its a 49er

[ACAMS]

Sure I'll give details

The inner exhaust liner is removed by cutting it away (you'll know what I mean when you start tearing into it)
and I epoxied up the water ports that lead to the mid (on the adapter plate) and drilled/tapped 2 holes in the back of the adapter to which I then used fittings and plastic line (all avail from any truck dealer) to dump the cooling water out.
This is called dry stacking. (the engine really crackles from this mod)
I have also recently add transom mounted water p/u and closed off the l/u water inlets.
The only reason for doing this is because the hull does not have a PAD and I was getting low water psi.

Hope this helps

So you didn't actually block the top holes and lower the water intake pickup then? ..... or does it still pull water?

Here is my project http://www.tinboats.net/forum/viewto...p?f=21&t=39587

[evilrude 1]

I epoxied all the water inlet holes closed and filled the water passage (under the water pump) with fiberglass right up to the 1/2 hole I drilled/taped for the water line going to the transom.
I can take a few pictures in the next few days if you would like.

[FMP]

ive been looking at this over and over again, and I cannot understand why the gearbox has been drilled in the exhaust area !!!
why do this when you have already taken out the can and put on a snout and drilled through the mid section ?
surely you get enough exhaust out the mid section with the snout or is there only a couple of holes that's not enough or is it all just for show realy /
dont get me wrong I think it looks great with the snout, but cant see the need for the gearcase to be drilled.

I going to ask the same thing .The snout out the mid seem large enough to flow all you need for a triple if the passage is that large to the leg. I'm guessing the holes came first and then the snout later or having only a few 1/2 inch holes made for a better combination of exhaust relief?

[ACAMS]

I epoxied all the water inlet holes closed and filled the water passage (under the water pump) with fiberglass right up to the 1/2 hole I drilled/taped for the water line going to the transom.
I can take a few pictures in the next few days if you would like.

Actually, what I want to know is can I epoxy the top hole will the bottom two holes give the motor enough water?

[sharpeye Mike]

Acams, block the 2 top holes on both sides, the 2 bottom holes will give you enough water pressure and it will not suck less air into the motor. I went a little further than that on mine, I blocked the three top holes and drill out the little drain holes on both side at the bottom of the water intake, it worked for me,



Here you go, sorry for the location of the pic.

I gained an additional 3lbs of water pressure and I run my prop shaft 5/8" bellow the transom. I have pictures of this but I'm on the wrong computer.
P.S. If you want to experiment, use silicon to block of the holes and water channels, it will last a long time and easier to remove if you decide to go a different route.

[ACAMS]

THANKS!!!! .... that is what I was hoping to hear!

Since I have several of these lowers, I think I will experiment with lowering the pickup like that.

[phillnjack]

All the modifications on this look very and well done. what gearbox is this from and what ratio are the gears.
At first I was thinking it just being another nitro gearcase with the holes drilled, then I noticed the bit about the 23p srx prop fits it .


here is my 23 srx on my own outboard, note this is the large club foot gearcase with the 2.42 ratio .
I do know this prop will not turn on a nitro gearcase as its diameter is way too much.
the 23 srx is 13 3/4 x 23. its the smallest srx that omc made.