Good info Andrew...On my stretch I have the luxury (enough room) to run a K&N stlye air filter and and I also have a 32T sprocket from Kings Custom. I am able to achieve 40mph. I attribute the majority of capablity to the sprocket. Having my first bike (The orange one) set up with a 44T sprocket as my comparison. The stretch cruises at 25-28mph at a considerable lower rpm. I dont run either bike at max throttle (I have, but not for any length of time), both bikes run the same NKG plug with Belder 7mm Premium Wire. I have ordered the new muffler from Dax in hopes of allowing the engine to breath a little better. I will update when I install it.