Stock exhaust question

[ElderGeek]

I have read on another forum that one can drill out the stock exhaust on a YFZ FoFiddy. When removing the end cap in my attempt to repair a dent in the outer casing I found I couldn't without cutting the end of the exhaust completely off and welding it back on.

I see a tube approximately 2" in diameter running about half way down the large chamber. It is capped in the end with two rectangular openings opposite each other on a horizantal axis. This are about 3/4" by 2".

It looks like a 1-7/8" hole saw would cut a nice clean hole through the "cap".. (1-15/16" if I could find one)

This would obviously increase flow and make the pipe much louder, but does this help gain any performance?

Will this help low, mid, or high end? No end?

Will drilling this out reduce the back pressure too much and cause other problems?

Rejetting would obviously need to be done when complete.

So is this worth the effort?

[dunerinaz]

Why not just buy a slip-on? They're not that expensive and will give a much better sound. Modified stock mufflers sound kinda crappy and if you ever do end up wanting to sell your quad you can put the stocker back on and sell the slip-on separate. I keep all my OEM stuff just for this reason. Just a thought.

[ElderGeek]

I plan on getting a Sparks, this would be a intermediate step if plausible.

I keep all my OEM stuff just for this reason.

I have too. I have every OEM part for it. This "opening" of the exhaust can be easily returned to stock if need be.

[Kramar119]

NO......don't do it! Modified stock exhausts look and sound stupid. Unless you are doing it for attention at the track......then drill away.