I purchased a Big gun Evo R Full exhaust for my 450... Its completely stock but im going to do this exhaust for now.. I cant find any jetting info on it. what jets to run.. can anyone lead me in the correct direction. I appreciate the info. thanks

 

Try a Dynojet stage 1 kit. If you really want to tune for best efficiency/power, you might try installing a "wideband O2 " kit. Really helped me tune my AC 500 ,I have an AEM, here's a pic. The gauge on the left. Dynojet's suggestion will be pretty close. I run a gutted exhaust and a K&N and 5 degree timing advance, kept stock pilot jet, used Dynojet's needle and spring, drilled the slide 1/8" and ended up with a Keihin 155 main jet, though I think DJ supplied a jet that worked. Realize DJ, Mikuni and Keihin jets have different numbers.