After owning the reed spacer for almost a year, I finally slipped it into my k5. It did make a difference and right where everyone said it would be, off idle and at low rpm. It was super easy to install, and gave me a chance to look very closely at my reeds. After 240 gallons of fuel through the bike, my reeds look like new. I no longer need the flywheel spacer, as my arms have gotton stronger, and this spacer seems to smooth out the hit a little. I put new rings in the bike at 200 gallons of fuel. When do you guys change the rings ?