Got my WR450 running near perfect finally. But that's when running. Still having issue with starting off the button. The PO apparently had engine work done to it by Eleven 10 Mod which is racing team mechanics company. There was a sticker on the cylinder from them. I have no idea what they did but expect the head or cams where modified for racing. I did complete rebuild in November and piston and valves were stock and head had not been bored. They bike will start off the button but not very easily. And when it hits the compression stroke it is very difficult to turn over with kick. I thought that was normal but compared to buddies bike it seems to have more compression. Eleven 10 mods offers head porting and also cam timing adjustments, according to their website. I can email you a picture of the head. It was not polished but might have had some material removed. The question is, what modification would likely make this bike so hard to start or give it increased compression? I heard they can also mill the head surface to lower the valves and increase compression that way also. I am going to call 11-10 and see if they keep work history but trying to understand the theory in these mods and how to undue them to get it to start.. I have soooo much money in this bike I can't give up now. Thanks in advance!!