Ms 250 muffler dissection

[Pioneer]

The parts of an Ms 250 muffler. The trio of holes in the forward part of the can are not stock, originally it only comes with the hole in the center. The usual steps on modding the muffler are adding the extra holes as seen here and opening up the gill slits. The latter are still in their stock form at this point.
Now that the muffler has been opened up, the baffle holes will be doubled up on the opposite side of the square tube section, and the gill slits widened.
When it is finished it will be sealed up again.

 

[Tom B.]

Nice write-up. I'll be doing this in the spring or when I can get to a friends with a heated shop. Doing the mod isn't the issue at the moment, tuning it afterwards is. Running it through some wood while tuning the carb to see how it runs while it's actually working, not just running.

 

[sundance]

@Pioneer, any more info or pictures you can offer up? I'm thinking in the spring when it warms up I'll try modding mine.
Thanks

 

[Pioneer]

I ground off the folded over flange on the bottom and the two sides with a bench grinder but left the top one on to help with alignment when it goes back together. Its actually kind of needed to hold the top edge of the deflector plate in place. The extra holes have been drilled and the gills opened up with a wood chisel in these latest pictures.
Make sure all holes you add are deburred to prevent anything getting back into the cylinder.





I will probably braze it up to seal it, cleans up the best this way.