Just wondering if anyone that races mx regularly has put a piston and rings in their 06 450f yet? If so how many hours did you have on it and if no one has yet how many hours do you have on the bike. I have 15 races on mine and alot of practices also:crazy: ,mine has 35.1 hours on it and seems to still be strong and pull hard. :applause: Iam so use to 2 strokes when I would put rings in every 5th race and a piston every 10th that I feel Iam neglecting my 4-stroke. Although I change the oil after every hour of riding and clean the ss oil filter,also maintain the airfilter.