026 muffler mod

peter399 · May 31, 2007

Hi all,

So, I figured I'd play around some with my old 026 I have.
Doing a muffler mod should be interesting. Browsing through the threads when searching for "026 muffler" I find noone with the same muffler as I have.
Attached are some pictures. Everyone seems to have the one where you drill 2 additional holes beside the original hole. On my muffler, there is a tiny exhaust in the corner. Thearea of the muffler intake is exactly the same as the cylinder exhaust port. So nothing to do there I guess? Shall I enlarge the existing holes or drill new holes in the fron of the muffler cover?

/Peter

peter399 · May 31, 2007

Also, the "cage" inside the muffler. Should I do anything with it?

Lakeside53 · May 31, 2007

Those wacky Euro non-spark arresting mufflers!!

The back section is the same as the 024 out here... Just cut the end off the box or drill it out.

The front is more of a problem... Look like the cheap design used on the 028's from the 80's. I'd weld in a correctly sized short section of pipe angled to defect the hot gasses. You could just wack a hole where the louvers are and rivit on a tab to deflect the hot gas from the case.

peter399 · Jun 1, 2007

Lakeside53 said:
Those wacky Euro non-spark arresting mufflers!!

The back section is the same as the 024 out here... Just cut the end off the box or drill it out.

The front is more of a problem... Look like the cheap design used on the 028's from the 80's. I'd weld in a correctly sized short section of pipe angled to defect the hot gasses. You could just wack a hole where the louvers are and rivit on a tab to deflect the hot gas from the case.

Thank you Lake! I will try to weld a pipe instead of the louvers, that was my idea also. If I take the same size as on a stock 262XP muffler, maybe that would be good. Or yet a bit bigger maybe. For the box, what you mean is that I should remove the side pointing away from the cylinder? (The side with no holes and leave the others as they are?

How much gain should I expect from these changes? As much as on a non Euro non wacky spark arresting muffler ?

BR, Peter

Lakeside53 · Jun 1, 2007

Just cut the end off the box, or the entire box if you can.

Timberwolf had a great thread a month or so back on the effects of various port sizes on an 026. You should check that.

I'd start with a port about 85% of the area of the exhaust port at the cylinder wall. In the USA modded mufflers there is one hole 3/8 inch diameter and two 5/16 inch or 3/8 inch. This is fairly conservative, but you can calculate the area from the sum of these three.

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