Stihl FS55RC KAT Muffler

[Cannon51]

The last time I used this trimmer it took forever to get it started, it would not rev up, and after using it about 5 minutes I turned it off and the muffler kept smoking like it was on fire. I took it apart this far thinking there was a screen that was clogged up but I have never seen a muffler like this before. Is there still something restrictive inside the main muffler? Is this something there is a muffler mod for, I hope? I broke one of the gaskets taking it apart.
Cannon

 

[HarleyT]

Stihl will tell you that you need to replace the muffler, but at $99, that is hard to swallow. If you were to go with the regular muffler, then you should switch it back to the basic ignition coil. E-bay has both fairly cheap.

 

[Cannon51]

This morning I drilled 2 5/16 holes through the back opening through the center divider connecting the chambers. Then I drilled another 5/16 hole in the outlet. I didn't get any pictures of the inside ones and the picture of the hole at the outlet is not very good. It cranked right up, I had to idle it down some after it warmed up. I used it about a 1/2 hour and didn't have any problem with it. I am going to look for a dead trimmer with a standard muffler but I can use it like it is.
Cannon