I've tried it all. Many things did not work, or worked in a way that made the bike less fun, or too limiting for certain terrain. The goal was to make it as fast as possible, with the widest power band as possible, and fix all the bug-a-boo's without buying my way out of trouble. I went down this path because the WR's handling is the most fun of all the electric start bikes I have owned or ridden.....which is ALL of them. It also retains the 'old school' ergos from 2003, which fits my frame (6'4") much better. It's easy to do a full weight transfer from peg to peg while sitting down, unlike the smaller framed 2012+ models. This allows me to keep the power on, when cornering, and the back end acts predictably everytime. Here's my final motor set up that is working very, very, very, well. Motor: 2007 YZ EX cam with decomp pin ground, stock cam timing (13 tooth spaces?). Grinding the pin correctly is trail and error. Removing 1.1mm is the closest spec I can give you. Stage 3 port and polished head. I did this to improve the flow, which in my humble opinion is not really an option if you go with any cam upgrade. It's a smooth rocket. YZ spec carb tuning (by passing ACV and going to the 100 pilot air jet) but with 165m/45p/NCVS on 4th/55 leak. 170/175m if you do the porting. Carb upgrades: 2008 CRF450R apump system, Tokyo mods pump arm linkage spring Airbox open to the subframe rails YZ spec exahust ( I prefer Dubach Racing, for the longer header, wider power band) Dynatek ignition using provided map 2 for off-road, massaged map 3 for chasing my street bike buddies (less low end though). Not a requirement, but it surely runs better than just un-plugging the TPS (dead power response at low rpms....) "Swiss Cheese" mod to the clutch baskets which includes increasing the oil passage way into the clutch area (+ ARC lever and Motion pro cable). A must do for clean shifting, starting in gear, and for being able to modulate the clutch in any situation. By-passing the neutral sense system. Starts faster and better without it. Polished transmission components. Again, not a requirement, but it was out for service anyway. Now it shifts like a brand new Honda..... Gear UP to 14/51; power delivery is so smooth. OEM clutch pack, or Hinson. Tusk, Rocky Mountain, MSMS, all suck.