To answer the questions...The KX 500 will pull it by 1/2 bike length until 3rd gear then the KTM catches and passes it !
I have run them side by side numerous times to verify with me on each one.Drag racing is different than racing though...for woods and hills I would choose the KX the power valve motor is a little smoother off the bottom with less wheel spin and just seems to be more woods friendly if you can call a 500 2-stroke friendly
and the KTM excels at MX and doesn't feel as big on the MX track! It now handles better than the 2003KX due to geometry and massive suspension upgrades!
The complete front end triple clamps, forks,axle etc are from a 2008 Honda CR250F with an excel hub and rim! The bike now has a oversize 270mm Gaffer batfly disc on the front and fork internals reworked by Factory Connection...I also changed the rear shock to a newer OHLIN that has been revalved for the 500 and my weight.
The swing arm is from a 1992 MX500 and rear disc and caliper are from the 94 KTM 550 there is no longer a torque arm link to the disc.
If you look close at the pictures you will see the Torque arm on the original going from the frame to the rear disc mount in my updated version I only have a kickstand there!
Torque arm is like the brake rod on old drum brakes!
The YZ is a fun bike but "NO" MATCH FOR THE KTM OR THE KX!
The white/red bike is a 2007 YZ450F I love this bike...Handles way better than the 500's and is just easier to ride..Will not beat the KTM or KX in a drag race but turns much quicker lap times in the 40+ class!