01' 426f with quarter throttle miss

Lee Gross

Hi Guys,

Nephew's new 426 with 4 hours on the clock has developed a miss. Bike ran fine at three turns out on the fuel screw. Changed the oil and pulled a filter skin and hello miss. Played with fuel screw but no change. Bike pulls hard and idles fine. Miss only occurs at steady quarter throttle. Ideas? Will try new plug next time out for starters.