is there any way of modifying the stock muffler to get more power out of the motor?

If you are talking about the steel mufflers, I've taken them apart and cut the baffles out. Brazed in new bigger exhaust tubes, etc.

They have worked fine.

Maybe not as pretty as aluminum?

Enjoy,

Jim

it is the steel 1s im refering 2 ... what would happen if i drilled a second hole and added a second tube?

how much bigger are the tubes u brased in?

I used 1/2" hydraulic tubing. Two of them. Worked fine for 25 -32 cc engines. You have some of the tube inside the muffler can like 1". this makes it sound a little better?

Enjoy,

Jim

cheers, i'll try this and hopefully it works

Be sure to Braze the parts with brass/flux. The solder will possibly melt and a steel filler rod will be brittle and break?

Enjoy,

Jim

did you put the tubes on the inside or have them poking out the side? and how long do you recommend each tube be?

The tubes are 2" long.

1" inside the muffler and 1" outside.

Enjoy,

Jim

do ya have a pic ... 4 a guide line, so i can see if i've done it rite?

did you take the plate with the nine holes in it out of the middle as well or did you leave that there?
if you didnt you put both tubes on the other side of the plate to the motor?

The mufflers I have modified were square box devices. I have done Homelites, McCulluchs, Weedeaters, etc. There was a baffle in everyone that I removed. The bolt-on ones had tubes that surrounded the retaining bolts to keep the muffler from collapsing when the bolts were tightened. These tubes need to be left in the mufflers.

The other tubes I was talking about are the exhaust outlet tubes.

Enjoy,

Jim

im new to this ... so wats a baffle?

Hi,

A baffle is a device inside the muffler to help cut down noise. What you want to do is completely "gut" the muffler. Open it up and take out anything and everything in there except for the two pieces of tubing that the bolts go through. These keep the muffler from collapsing when you tighten the bolts. Then put it back together, drill two holes for your outlet tubes, and braze or silver solder the outlet tubes in. Here's a couple of pics. The last one is a custom muffler I built for my Katana.

Good luck,
AV8TOR

here are some pics of the muffler in question ... its not held on with bolts, but instead its that wire and spring that runs around it.

when i pull it apart i take out a plat and a tube is this rite? then im going 2 add two 1/2inch tubes at 2inches long each. is this also rite?

im new to this so sorry if these are stupid questions

In your case there probably aren't any tubes inside to worry about, but just take out anything you find inside. You want just the empty shell. Then yes, just braze or silver solder two 1/2" tubes in for exits.

Good luck,
AV8TOR

is there anything else i can do to this motor to get more power?

Looks like a McCulloch 28/32 engine

Get rid of the screen

those photos are of the 32 cc mac motor straight out the box ... now it has a modified muffler ... will post photos next week sum time with the new muffler on it and with it assembled on my bike

here are sum photos of it on the bike ... but the modified muffler isnt on ther yet ... does smoke the tyres with the stock muffler though, but it stinks afterward

Maybe the smoke is from improper contact between the output shaft and the poor bicycle tyre?.....