muffler for gas boat

I've got a Zippkit gas boat with a McCullough 28cc engine, bought used. Just lost the muffler in the lake. Want to try building one instead of paying the bucks to buy one. Any one done this before? How? What do I need to know? George

It will probably cost you more for the material than you will pay for the muffler.

Most material suppliers have a minimum charge, and then they will charge you $7.00 to $10.00 for a cut. You coule easily have $40.00 in it, then you still have to machine it.

The muffler shown in the photo is a copy of the Samba touring car muffler. It reduces the 95 dB sound level measured at 50 ft down to 82 dB. It is made from a standard aluminum tubing (1.500" OD X 1.430" ID X 5.375" long) available from McMaster-Carr. The three baffles inside are machined from bar stock & are held in place with #2 sheet metal screws. The machined ends are also held in place with #2 sheet metal screws. Each baffle has one .500" ID hole. Two holes are drilled off center & one hole is in the middle of it's baffle piece. The baffle with the hole in it's middle goes in the middle of the muffler. The other two baffles with their off center holes are positioned 180* from each other & equally spaced. The entire muffler & its mounting hardware weigh 4.4 ozs. The muffler shows a 1/2 HP decrease in the 22,000+ RPM range.

Jim Allen

Now Mr. Allen - there is something of yours I can finally build and try.

Although I think I will use 'spacers' between baffles to cut out screws - (except for end caps)

Good idea Thank you Sir

Cheers

Good idea. The spacers can be drilled with lots of lightening holes & still do what is intended. Three feet of the tubing used was about $15.00. You can build everything I have posted with a little effort. Learning to do this will give you the highest quality stuff possible plus save you a great deal of money & aggravation! For example, I have made the ball & pin universals only two times in more than 50 years of boating. I'm not making them now because any part wore out. I have more test stands & boats where they are used. JUST DO IT!

Cheers,
Jim Allen