So to start it off I have a J&T can and the packing material was rattling inside the can a bit so I went in there with a welder and welded it an a large washer with the biggest inside diamter I could find that fit in the bottom of the pipe and welded that in there thinking cans are supposed to lose power from to little back pressure so this will add just a little bit and not make a difference. The sled never had problems before and I took it out today in about 8-10 inches of fresh snow and it felt like a dog, couldn't pull the ski's up and would only get about 7800 rpm then dropped down to between 7000-7500 and hung in there. I went and then put my stock can on and it held 8100 strong for the next couple hours in the same conitions and I could ride wheelies again no problem So backpressue is good on 2 strokes but you can go to far really quickly I found out