Since all three bikes supposedly share the same engine except for the ECU I do believe this will be the best uncorked WR ever. Once you remove the normal garbage, change the pipe, and put an ECU from the FX in it it should be very comparable to the FX except for some additional weight and a heavier flywheel. So you have to ask yourself do I want to buy a bike that cost $100 more only to put several hundreds more into it to make it like the FX. Why not just start with the FX and add a good light? The flywheel on the FX might be an issue to some people since the weight is the same as a YZ. One of the things I love about the FX is the acceleration. It winds up so fast but with control and just feels amazing. I've had nothing but rain and snow so I've only ridden in mud and I have had no problem controlling the beast. My question will be how does it handle in some gnarly single track with a lighter flywheel? I won't know until spring. You can always add a heavier flywheel but I hope I wont have to because I love the acceleration so much.
I believe the flywheel as well as all the engine + transmission components are identical to the wr. The only thing different between them is the headlight, tail light, dash display, FI light low, fuel light, tail light and rad fan.
Difference of 9 lbs.
Oh and the exhaust.
But mechanically the FX shares the same crank flywheel stator and cams as the WR but the WR Has a non tunable ecu.
So if you replace that and the exhaust you got the same thing as the fx with the headlight and other goodies