03 xr100 - anyone know 'free' mods?

Pull the snorkel off the top of the airbox to start. You can either drill some holes in the top of the box or get some of the foam buttons such as "Bulls Eyes" which require a 1.5" hole to snap in to. I believe alternate jets are available from Honda but I doubt they are free. The stock exhaust looks like it could benifit from some grinding of the welds where it bolts to the cylinder. If you get to where you want some pay for mods that really get you some bang for the buck Eric Gorr's Forward Motion has caged Rich and he created some insano power on both my XR284 and my son's XR95.