I have been poaching around here for the last couple days because I just picked up a used 2009 wr450f. Totally stock, still have original pos rear tire and sadly I believe it still had original oil (disgusting) and air filter in it(filthy). I was able to ride it for a little bit and the thing was overheating, to the point I was worried the cylinder head was going to melt. 40* day @ 3000' and mostly in 1st/2nd gear. Every time I would stop my right rad would start steaming from boiling over (I just put the bike in the garage to start the uncorking and noticed my overflow tube wore through at the rad and was spewing fluid down the fins instead of back to the reservoir). But the fact still remains it was blowing past my rad cap because it was overheating. I figured that I shouldn't be overheating because I did have some air movement and it was 40*, but my previous bike was a 2000 cr250r and I never had any issues. I know they are two different beasts, so please feel free to treat me dumb because as far as this bike goes I am. I'm thinking that I am running lean due to the heat. The bike won't hold an idle without dying, and it pretty much needs the choke on to run without giving it throttle. When I'm on it riding everything seems fine to me, but this is my first four stroke. Anyways, I have been looking how to uncork this thing, and as I was starting into the tear down process, I got the air boot of the back of the carb so I could get at the it and I decided to give the throttle a twist to see how bad the throttle stop screw messes with stuff. And as I gave the throttle a twist, it completely opened. Needless to say I contacted the previous owner to verify nothing had been done to the carb, he said nothing totally stock.(ais still in place). Now I'm at a loss, I feel like I still need get into the carb to rejet (which I know nothing about or how to do it) and while I'm there verify the shorter stop screw, but maybe I'm missing something. If the throttle opens all the way, that pretty much means it has already been changed correct? And as far as me worrying about the cylinder head over heating, it appears to me to have a dull almost pinkish hue to it, not like the semi gloss silver on the crank or the valve head(?), is this normal? I also just picked up a new msr battery because the one in it was dead. I put the new one in and it just clicks rapidly, but if I run a set of jumper cables from and extra car battery I have it will engage the starter. After I had it on the charger for a couple hours on a 2 amp charge, it would read 11.4v. Did my local shop sell me a bad battery or do I need some special battery? Given that I would be normally riding 0-4000', would me installing all the parts in a gytr ais delete kit have me jetted correctly, or should I go a different route? I know I just wrote a novel, and I'm sure I've even forgotten something. Thanks in advance.