A buddy came over today with his brand new 545. Still no oil or gas in it. He wanted me to do a MM on it. He had ordered an extra muffler to modify and keep the original, original... He isn't getting it ported and didn't really want a radical modification, just something noticable and effective for his otherwise stock saw.
Since the stock outlet and deflector is out front of the brake handle, I bent the deflector up and opened the hole to about twice the size of the stock opening. The internal baffling is a multiple tubular runner set of six passages to the output chamber that looks like it will flow well with the output hole being the limiting factor.
Before hogging out the hole. It got opened up clear to the rear of the deflector while still allowing the screen to be inserted. The lightest color is the interal baffle under the hole. I somehow missed getting a picture of the opened up hole.
A picture of a couple of the internal tubular runners from the primary chamber to the secondary chamber. It looked like there were six of these, all of equal length, three on each side.
A gill slot was put into the primary chamber down at the front end furthest from the exhaust port to lower peak pressures inside.
Ended up as a not in your face, just a little noisier than stock (not much) but should suit him fine as he is in a residential area. I didn't get to play with it to see what gains are there, but I'm sure there are gains over stock.
Echo 4910
