I was just wondering exactly what the outer shell of the stock silencer is made of. I plan on modifying the inside of the silencer like Gabe has done. What would be the best tool to use to cut the outside part off? And to put it back together? Anything I should special I should know about disassembly and/or reassembly?

I also have another question. When modifying the spark arrestor, what exactly do you have to do? I have seen pictures of a modified one, but I'm not sure what to do. Any help you all could offer is greatly appreciated. Thanks.

 

As far as I know, the outer shell is made of steel...nothing fancy. I had the mod done on my silencer at a local muffler shop though--the owner is also an off-road rider--and I just printed out Gabe's pics and showed him what I wanted done. Cost me $20...

With the endcap, a while ago I had a friend cut off the spark arrestor and restrictor, and then had him re-attach just the SA--this left the endcap with a huge opening without the 1" center restrictor piece. With a stock motor and no other silencer mods, I wasn't real impressed and thought it sounded like crap (louder but more like a "brappy" exhaust leak sound), and felt absolutely no gain in performance. In fact, GT Thunder has a dyno run with and without an endcap on a stock motor and un-modded silencer, and there is no difference in HP--proof that the silencer itself must be opened up to flow better.

Since you have a modded engine such as mine though, I can tell you that a modded pipe per Gabe's drawings definitely flows better than the stock set up, and after this mod will end up with a better flowing silencer without the loud noise associated with aftermarket pipes. As far as modding the endcap, today I installed my SA-only endcap and could hear a definite increase in noise, but didn't do any riding or runs as I'm still breaking in my new motor. Not sure it would make a big difference though...