Dolmar 6400 muffler mod

[stihl saws]

A few pictures of the inside of a 6400 cat muffler. This thing is really tough to uncrimp. The exhaust port of the rear part is almost 3/4". It should be big enough.
Then there's a spacer that acts like a air gap type of heat sink, probably to block the the cylinder from the excess heat built up from the cat. Thinking I'll keep it in there.
We know the cat part is not going back in.
Then the front part. I kept the baffle, but bored the holes out to 1/4". Stock was about 3/16

 

[Adirondackstihl]

Cut that baffle right outta there.
keep those little ears though.
You'll need em for spacers. I brazed em on.

 

[NCFarmboy]

Cut that baffle right outta there.
keep those little ears though.
You'll need em for spacers. I brazed em on.

Same here on 3 of mine.
Shep

 

[Wilhelm]

I left the cage in but opened it up a fair bit on my Dolmar PS-7900.
I kept the cage to prevent too much heat directly hitting the frond half of the muffler.

Muffler cage (modded):


Muffler outlet (stock/modded), kept the ability to use the stock spark arrester screen:

 

[stihl saws]

I ended up keeping the baffle in, but bored about a 1 inch hole in the bottom of it with a step bit.

 

[fordf150]

I remove the 2 baffle plates, cut the bird cage out from between the stand pipes leaving the edges of the bird cage that is welded to stand pipes. that keeps the tabs in place on the end of the pipes for proper spacing. I also just leave the outlet alone.