My 2002 Warrior has a Big Gun silencer with a Pro Design filter kit and a stock airbox. I'm running a 150 main jet. It seems to run good in the lower gears but doesn't seem to wind out quite all the way in 5th or 6th. The plug looks good, being a light tan/beige colour. Big Gun recommends a 147.5 to 150 main when you install the silencer.
Since the plug looks good, do you think I should still try the 147.5 main or will that be too lean? Should I be afraid of burning the valves if I go down only one size to the the 147.5?