I put a K&N filter on my 425 Polaris it made the worlds of dif on bottom and mid but seemed to loose topend.I havent rejetted my carb.What i need to know is how far up should i go?It has a stock 140 jet now does anyone think a 150 or bigger?Dont say check the plug ....its a %$#%$# to get to.like to change it right the first time.All input apperciated. -----------------------Brad 1996 425 Magnum----1996 400 Sportsman----2001 Breeze