I have a 10hp Copperhead. I've kinda figured out how I would like the exhaust to run. Basically just trying to get the exhaust pointed towards the back. Right now the stock muffler is out towards the side.
I'm planning to use the same size tubing, but the problem will be the muffler. Can I just buy something off the shelf or do I have to get one made, if anyone makes them.

I'll get some pics,of the location and how I need it mounted, soon.

I used a aerosol can to mimick the muffler idea. I think there would be less bending and would be fairly easy to install.
I've dropped MarshMellow an email and am awaiting to see if they would build a custom header/muffler for it.
Any ideas of anyone else that would/could do this if MarshMellow doesn't?

Suggestions/Comments are also appreciated.

You tried talkin to Cody? Doesn't he mess with those lil engine's too?

I would say go for it. Cut an exhaust flange. Buy some stainless tubing from columbia river mandrel bending and make a resonation chamber with some baffles in it. Make sure your volume flowing through the baffles is > or = to the volume through the primary tube to keep good performance. The more you deflect the flow the quieter it will be.

Mag10

If you are using holes in a plate as your baffle, make sure that they open flow area equals the amount of area in the primary tube. If you have an 1" primary, your area is .785 sq in. (A=3.14*R squared) So, if you are going to drill .250 dia holes for your baffle, you need a minimum of 16 holes to = area. In the past, I have used a plate with holes in it and redirecting plate over the top of it. Also, the longer you can go with the primary tube, the better off you will be.

You can calculate the ideal primary length if you know

Stroke: (Inches)
Bore: (Inches)
Number of Cylinders:
Exhaust Valve Diameter: (Inches)
Exhaust Valve Opening Point: (Degrees )
Exhaust Valve Duration: (Advertised)
Exhaust Valve Centerline: (Degrees)
Peak Power RPM:
Volumetric Efficiency:

This usually yields a primary too long to package on a mud motor

PM me with your email address and I can send you a sketch of what I have done in the past.

Mag10

Yeah, Cody. SETX Performance...50hptiller

I know he has messed with some exhausts, and I thought he did some dabbling with Karts or something and may have some experience with those lil engines.

robertson torque tubes makes pipes check him out.

you can get sections u can weld together

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this is what i did to my 6.5

Looking at the muffler I have now on it, it has 24 holes @ 3/16" and 6 @ 1/4".
That is just guessing the sizes.
If I match the same holes and sizes, I should be able to keep the same backpressure. Right?

Seems that muffler has just the primary pipe going in and all the exhaust collects in the can. The 2 tubes for the outlets have the holes drilled in them on the sides(6 rows of 2). Each tube has a baffle plate with 3 - 1/4" holes in it(making the 6 @ 1/4").

Would a longer primary change the baffle hole number? What about the lenght/size of the muffler chamber?

I was over at Copperhead yesterday and happened to ask about this. They pointed out that they are no longer mounting the mufflers pointing out the side. They actually flip them and mount them facing down now. They showed me one mounted this way. Gil's son actually seemed to think this wakes up the engine a tiny bit.

Keep us updated on what you come up with

I haven't done anything yet. Still deciding on design of the baffles and looking need to go to a muffler shop to see if I can find some scraps. Also I don't have a welding machine so I'll have to get someone to do that for me. May just go and talk to someone at the muffler shop about it and see what they would charge.