YFZ experts, please help it's not running good!

[the-ex-files]

My buddy recently got a YFZ 450. A very nice ATV, and I was very impressed. It ran good for about the first week or so, but recently we can't get it to idle at all. To start it you have to have the throttle in about half way, and always be on the gas. Also we can't find the idle adjustment screw anywhere. Where is it? Another thing, when we were out night riding, I looked over and seen his header pipe glowing bright orange. He also said his fan has ever kicked on? So we took it back to the dealer, which was very busy and they said it would be a couple of weeks. So I until we get it back,I am asking you YFZ experts your thoughts on went wrong.
Thank You.

[quadnice]

sounds like the jetting is off
go up a size or two for the pilot & main
possibly lower the needle clip position too, if the jetting does not help it
Order a Zipty air/fuel mix screw for easy adjustment anytime, & anywhere. -The carb is crammed in it's location good, so the less you have to take it out for adjustments, the better! I believe C&D Racing sells the Zipty's.
The idle adjuster is a dime sized -Black knurled edge knob on the left side of the carb, about half way up, close to the edge of the rear fenders side panel plastic. You'll see it -the plastic is barely hiding it.

[brazilian rider]

I have to start mine revving a litlle bit too. All my quads are like that.
Isn't it normal???

[Jonas]

Take your carb off and clean it. Slow jet clogged??

[jarsong]

Originally posted by the-ex-files
My buddy recently got a YFZ 450. A very nice ATV, and I was very impressed. It ran good for about the first week or so, but recently we can't get it to idle at all. To start it you have to have the throttle in about half way, and always be on the gas. Also we can't find the idle adjustment screw anywhere. Where is it? Another thing, when we were out night riding, I looked over and seen his header pipe glowing bright orange. He also said his fan has ever kicked on? So we took it back to the dealer, which was very busy and they said it would be a couple of weeks. So I until we get it back,I am asking you YFZ experts your thoughts on went wrong.
Thank You.

Bump your idle up about 10 clicks and test it again. The thing is starting to break in. Also mine runs like crap when it's cold and this appears to be normal. I have to baby it until it starts to generate some heat. This is a race bike with a racey cam, it's gonna shake a little when cold... Also, the glowing head pipe is also normal for this bike. Here is my recommendation to make it run right:
270 foot elevation, temp at 60-70 when tested.
Mod's are:
Cam Mod
No lid on Airbox, sparky removed from pipe.
GYT-R air filter
165MJ (Summer) 168MJ (Winter)
45P
YZ Bike needle in the 4th position....
2 turns out on the fuel screw.
Tested the 165MJ tonight with great success.
jarsong