polaris rmk

My 2012 pro RMK will be running fine and then run like **** until it dies. It gets worse at higher RPMs. It is throwing a Code DX7. It is the second ride on a top rebuild. anyone got any ideas?

http://minneapolis.craigslist.org/wsh/rvs/3519819943.html Sled has stage 2 BMP bolt on kit. Ceramic coated Pipe & can, v-force reeds, PCV, billet head, high and low compression domes, scs sled wrap, mtn addiction cans. -RIPS!

http://minneapolis.craigslist.org/wsh/rvs/3519819943.html

4400 miles. In excellent condition Motor just has been rebuilt with the big bearing kit done last year by Indy Dan. Primary clutch balanced by Indy Specialty as well. Then I bought a Pro.. '09 front end upgrade, to include spindles 5"inch handle bar riser Carls vented sides. Projector beam...

My dad bought this sled mid season and put 280 miles on the sled, he doesnt have time to ride it due to busy at work. sled is not even broke in yet! He owes 10,500 on the sled so thats all he is asking for it. thanks for looking and pm me for more info and pics!