Pre EPA 026 muffler compared to new 260 muffler?

[rustyb]

Just curious what the differences between those two mufflers are. I understand the 260 muffler was restricted so the saw would run hotter therefore have fewer emissions but just how restricted in terms of opening size compared to the older 026's?

 

[Jacob J.]

Rusty- the pre-EPA mufflers were open, the EPA mufflers have a heat shield now which must be opened up when porting/modifying the saw.