OMC Exhaust mods? I know...

[Matts94z28]

Every thread I find is archived without pictures. I am wanting to make some noise with the old fast strike. Does anyone have any pictures of an OMC to show me exactly where to drill/cut?

Not looking to take the power head off and remove the can just yet.

Thanks all!

 

[atc250r]

I went with a Bob's Machine exhaust snout. The plugs that come with it to block it off are crap, I'm going to make one out of a piece of aluminum plate for this season.

http://www.bobsmachine.com/Products/engine_exhaustHousing.cfm

It comes with pretty clear instructions about where to make the hole.

John

 

[Matts94z28]

I went with a Bob's Machine exhaust snout. The plugs that come with it to block it off are crap, I'm going to make one out of a piece of aluminum plate for this season.

http://www.bobsmachine.com/Products/engine_exhaustHousing.cfm

It comes with pretty clear instructions about where to make the hole.

John

I ordered one and had some issues with it not shipping and just got my money back.

I've seen people say you can drill out the existing holes at the top of the mid for more noise. I also read that people drill right through above the cavitation plate and I have also read people say to drill up into the mid from below.

Bob's picture shows that you would need to drill in the center of the mid if i am looking at it correctly. Same with the Yammy housing.

 

[atc250r]

Yeah holesaw through the back. Pulling the lower and putting holes on each side just below the cav platelike iI've seen discussed on Scream and Fly is a good idea too if you want quiet at idle/low speeds. Then a strip can be made to easily block it off when you wanted to shut it up.

 

[Matts94z28]

Yeah holesaw through the back. Pulling the lower and putting holes on each side just below the cav platelike iI've seen discussed on Scream and Fly is a good idea too if you want quiet at idle/low speeds. Then a strip can be made to easily block it off when you wanted to shut it up.

Just found a few good pictures over on S&F. I wouldn't mind doing a hole saw through the back at all to be honest. Was it just dead center above the curve on yours? How large of a hole?

I can always weld up something similar to what Bob's makes for the integrity aspect. My uncles old merc had the holes up top and he ended up with a cracked mid. Then again he made a ton more power and had a much faster hull.

Thanks for the words.

 

[saxmanbrad]

At first i drilled through those two holes further up the shaft, didn't add much more noise, then used a hole saw and did two large holes down in the lower. Quiet when slow, screamin when screamin!

 

[atc250r]

I think it was a 2 inch holesaw they said to use. If I were going to make the hole like that I'd give Bob's another shot at getting a snout to you. It makes it look a lot cleaner than just a hole blown in the mid.

 

[Instigator]

The ones...

just above the cavitation plate are good as they are under water and quiet off plane. You will not p/u any power, only noise.

I have a website w/some info on modding OMC's.

http://2strokeonly.com/

 

[Matts94z28]

just above the cavitation plate are good as they are under water and quiet off plane. You will not p/u any power, only noise.

I have a website w/some info on modding OMC's.

http://2strokeonly.com/

Awesome! I favorited the site.

I made three 1/2" holes in the lower for now. I will try it out this weekend. This way I can tap the holes and place pipe plugs in them if I try the bobs snout again.

 

[Matts94z28]

Anyone know what the deal in on the exhaust tuner on these motors? I have seen conflicting information. Some even state that there is not a can/tuner in the mid on these... seems crazy to me.

Not that I am looking for a tuner or anything, it just drives me nuts that I can't find the information.

 

[atc250r]

Can you tell by looking at the online parts lookup diagrams?

 

[Matts94z28]

Can you tell by looking at the online parts lookup diagrams?

Haven't been able to find any good exploded diagrams of the mid section for this motor. Plenty for the lower unit and power head though.