Taking out the packing on stock muffler

[hjsmith00843]

Running out of funds and I need to get a little more hp. If I grind the welds down on the header and remove the packing from the muffler will I gain some power with a jet change?


Noise is not a problem.

[BlasterEaten250]

There is no packing on the stock muffler, only chambers

[hjsmith00843]

Originally posted by BlasterEaten250
There is no packing on the stock muffler, only chambers

oooo that tells you how much I know about atv's and how new I am. Is there anything you can do to a stock 400ex muffler to get a little more power?

[tri5ron]

Originally posted by hjsmith00843
oooo that tells you how much I know about atv's and how new I am. Is there anything you can do to a stock 400ex muffler to get a little more power? not if you want it to still be legal

[bkelley]

Removing the packing from an exhaust will only make it louder. Like Blaster said, stock exhausts don't have any kind of packing, they are made up of metal baffling and passages. Which results in a quieter and heaver exhaust. Most aftermarket exhaust will come with a fiberglass type packing that acts as a baffle and dampens the sound. This makes the exhaust lighter and louder.

If you want a little more performance and a better sound from your stock exhaust, you can check out the Phoenix performance exhaust inserts (http://www.quadcommand.com/Phoenix_400ex_Exhuast_Insert_p/psa-400ex.htm). They have built in spark arrestors so you'll still be 100% trail legal.

[sc400ex_rider]

you can take the end cap off and drill about 10 1/4" holes in the chamber wall. you will need a long drill bit. it really reduces back pressure. you can tell the diff. the small holes help baffle the sound. i also cut out the small outlet pipe on the end cap. this was hard because of the spark arrester screen. it was hard to remove in one reusable piece. i welded it back on so my system looks stock and still has the spark arrester on it. its not very loud just gives it a nice rumble.