Help with a muffler mod

[Hudson63]

Ok so here's what I got. Picked up a husky 61 cheap but it was blown. Picked up a 272 jug and slug. Also had a 272 carb and other misc parts around. For starters the plan is to check the squish remove the gasket if possible, add an 8 pin sprocket, and mod the muffler. From what I have heard you should open the exhaust 80-90 percent of the exhaust port. I removed the screen and gaurd but need to figure out how much to cut out. I used the shield as a pattern but it's shaped odd and is hard to calculate. The paper cut out is roughly my exhaust port size. So can someone help me figure out what to saw out. I don't wanna go too big and turn my piston into a crispy critter. Thanks for any help

[Hudson63]

and if someone could help me upload the pictures of what I got that would probably help

[Hudson63]

Well I can't figure out the pic thing. But to put it roughly if I use my shield as a pattern I end up with roughly a single 3/4 inch hole. What do you think too much or not enough?

[isaaccarlson]

Don't worry about size too much, just put a hole in it.  I used a 1" piece of ½" electrical conduit on my 390 and that worked great.  I brazed it on.  I needed to direct the exhaust gasses away from me, and that did the trick.  It looks stock and blows the exhaust out over the bar to the right.  I completely gutted my muffler as well.  Just get the exhaust out of there without melting or burning anything.

[isaaccarlson]

Here is a pic of my personal muffler.  I pulled it from a youtube vid, so it is grainy, but you can see what I am talking about.
The pipe shoot the exhaust over the bar from the top corner of the muffler.  This vid was of my 28" bar when I first got it and things were not broken in yet.  You can see the size of the chips it was pulling out of frozen maple.  The rakers were filed down a touch too far and it pulled a bit hard, but the next sharpening fixed that.