Muffler modifications

[timberfaller390]

What are some mods for the muffler on a Stihl MS390, do you just knock the baffles out or is there a certain way they should be cut or what?

[sawguy21]

Just keep cutting until the noise outweighs the gain in power then buy a new muffler and make one less hole. smiley_horserider Seriously, it is  matter of trial and error until you are satisfied with the results.

[johncinquo]

JB weld plugs extra holes excellently!   :D

[timberfaller390]

So what exactly do I cut? Is it the baffles or do I just drill extra holes in the front of the muffler for added ventilation.
John I tried JB weld on my jeep tail pipe and it burnt off in short order.

[Al_Smith]

 Oh there must be about 10 thousand posts if not more on doing a muffler mod on nearly  every web site that deals with chainsaws .

What do you want it to do ,run a little better,run a lot better ? The more baffling you remove ,the louder it gets .Same with increasing the hole size or enlarging the hole .

Try just pulling the screen and see how that does first . You have to increase the fuel flow when you get to decreasing the back pressure or else the engine might run lean .Not good .

Because of so many nay sayers and sceptics I'm not going to walk you through it .I will say this much on mine there are no baffles what so ever and the discharge is about 80 percent of the area of the ex port .Those are on modified saws though . Having said that ,what I do to my saws and what anybody else does should not influence what you do to yours . Research it a little before you start discecting that muffler .