want a four stroke?

Its not you. A two stroke MX bike isn't designed to idle, it is designed to be run wfo. A YZ250F is a good choice, but you may be happier with a WR250F. From what I understand, the bikes are pretty much the same except for the suspension setup, different engine tuning, and the lights on the WR. I hear that the WR is pretty good on an MX track too. Hopefully someone will chime in and tell you better than I can.

Good luck on whatever you do,
Joey

About the idle you speak of..

Its not exactly 2 strokes in general that dont have any idle, its mainly motocross bikes.

My KDX is a 2-stroke "offroad" bike, and it has rather excellent idle.

But I would imagine that a 4-stroke motocrosser wouldnt have nearly as good idle as an offroad, but however better than a 2-stroke mxer..

My Cr250 used to die when I first got it because the idle was set too low, I turned the idle up and have had no problems! :thumb: I ride my 250 with my son who rides an XR100 and have had no problems there either, just gotta work that clutch alittle more with the two-strokes since their flywheels are so much lighter and don't have the engine braking capabilities like the four-strokes do.
If you want to ride motocross then (in my opinion) get a motocross bike. I've heard of too many people getting "off road" bikes that eventually end up getting an MX bike. As your skills improve on the MX track, you'll more than likely do the same. I think it's easier to fart around on the MX bike with the kids, than it is to ride a non MX bike on the track.
Just my .02 cents though...

got a '98 KX 250, idle is fine.. can start it without any probs, and with no choke i can let off the gas even when its cold and it doesnt stall... i dont usually let it idle tho, when i start it, im usually going right away. my friends uncle just bought an '02 KX 250, which was having the same problem, but we just turned the idle screw and now its idleing fine. if its not idling and u need it to then just turn the idle screw... maybe get it jetted