James Sawyer
ArboristSite Operative
Finished my dual port 361 muffler mod. Installed a West Coast port. I cut and folded in a louver opening facing the front of the muffler, the area opening is ~ .63 in sq. (~the area of 7/16 hole). The open set back off the face of the can is .700" would have prefer to be at 1.0" but with the can seam it was limited. Looking at it now I might have gotten away with .900". I thought I'd start with that, 7/16" area opening its would be easy enough to open it more if needed. I wanted to get the reflection off the front of the can before the exhausted exited. I believe it will help with the noise and keep more of the back pressure and fuel in back of the cylinder. Guess we'll see how this works, I should have ran a test cut prior but didn't, I had the saw tore down for a good cleaning, clutch bearing lube, a full warp handlebar upgrade, felling spikes, bigger chip cover and 28" light weight bar. The muffler mod was one of those last minutes decisions. Adding the deflector in with another WC parts order. The goal is to get a little more heat out of the saw .. maybe a little more power assuming 5%? These WC deflectors require a little body and fender work them to sit flat if you use the threaded rivets. They bend easy enough to shape to the can. I chose the rivet option because I wanted to run the screen. Just to put it out there... I'm not sure how this will work out! I'm not going have any performance data... some muffler mods work some don't. Saw with modified muffler can burn more fuel and less performance. I'll post once I get the saw back together, tuned, I'll do a test cut. This is my main go to saw so I should know if it helped.