Stock exhaust insert.

Run across this just now wondering if anyone has tried it or some feedback. Sais fits WR250R
http://www.motosport.com/pro-circuit-quiet-insert-with-spark-arrestor

It fits the WR250R if you have a ProCircuit exhaust....I doubt it fits the stock can. If you want a more open exhaust with the stock can, get the Graves Hi-Flo insert. Mine has one on the stock can. I've since installed a Q4 and I don't find it's much louder than the Graves insert on the stock exhaust.

Link: http://www.gravesport.com/Graves-Motorsports-Yamaha-WR250R-WR250X-Hi-Flo-Exhaust-Insert.html

I have the graves also, works fine and not too loud.

The Pro Circuit insert is intended to quiet a noisy muffler, not open up a restricted muffler to add power. I can't imagine how it would be useful paired with the stock WRR muffler.

The Graves insert is intended to open up the stock muffler. Unlike the stock muffler, or the Pro Circuit insert, the Graves insert doesn't have a spark arrestor.

Mine does, I went to the dollar store and bought a stainless sink screen and used a stainless clamp, and put it over the muffler side of the graves cap, didnt hurt anything and its legal, works just fine, I also drilled a couple of holes in the baffle which opened up the stock muffler, she sounds purdy hahahaha

Hmmm misleading Thought I found a deal.