# DIY 1k exhaust mod



## JPs300 (Mar 23, 2011)

Decided to cut the end of the muffler open on my bud's(blknite23 on here) '12 1k outty XT to see if we could do some sort of simple mod to open it up a bit. - On my 800 I simply cut the back end off the muffler which removed the spark arrestor/baffle assembly. Added a little rumble w/o being overly loud for night rides out in the country. I welded a plate back on the end with a short 2-1/4" snorkel for looks. 

Un-bolted the tip & removed the spark arrestor screen & was simply looking down an open/perforated baffle tube. Busted out the plasma & cut the indention out of the back of the case to get it open & see how it's designed. - Was getting ready to take off on a ride so didn't think to snap pics while I had it open. Simply put, the muffler is a chambered design with packing in the center chamber and three pass tubes. A perforated entry tube feeds straight through to an open chamber in the back(the perforation allows "breathing" out into the packing in the center/main chamber), then a smaller perforated pass tube passes back through to the front in a chamber opposite the rear one(perforations again allowing breathing out into center packed chamber), then another large perforated tube feeds out to the exit. 

All that means, if you simply drill/cut a hole in the bottom of the outlet tube you open the muffler straight up to the rear chamber, thus eliminating a large portion of the restriction of going back through the small middle pass tube. - I'd recommend starting around a 1/2"-5/8" hole and stepping up if you want louder. If you get too big/loud for your taste a small plate can be spot welded back in to cover up some of the hole, but it doesn't take too much of a hole to get pretty loud pretty quick as you bypass a large portion of the muffler. 

Pic showing piece I cut out/welded back to look inside: 









Roughly "quarter" sized hole I cut out(plasma cutter) in the bottom of the tail-pipe where the screen goes in: 










Very noticeable difference in volume & nice throaty sound. A bigger hole would allow it to be even louder, but this was plenty for what he wanted. 

Sorry, was heading out for a ride & I was lazy so I didn't record a sound clip. Just a simple "free" DIY mod to open up your factory exhaust a little & add some rumble.


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## jrpro130 (May 10, 2009)

Nice work! I did the same/similar on my renegade exhaust. Cut the whole top part off, gutted it and blasted some holes in it then re welded...good stuff!


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## Polaris425 (Dec 16, 2004)

Cool!


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## Blknite23 (Apr 11, 2013)

Thanks JP!, i ended up making a slight adjustment and with the spark arrested installed, the bike has a nice little rumble to it. not enough to make the neighbors mad but just right....


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