Yes, I did the reed spacer, FMF Gnarley pipe, and the flywheel weight. I'm after more low end and that's what it gave me. My bike will still go faster than I want to go. Just doesn't get there as quick. Not a good comparison, flywheel weight gives more mass to the flywheel and crank assembly therefore the RPM's don't spin up as fast. Reed spacer puts the tips of the reeds back out of the turbulence of the air/fuel mix in the crank area before it goes into the combustion ports. Thus giving it a little more low end power. That's my lean on the spacer. One of the racer guys might have a little more insight about it.