You crazy mo fo!!!!
You decided that a 490 is a good starter bike?????????? Just wait till your riding off road somewhere, casually in 4th, with your hand off the trottle (they seem to make all kinds of power at idol) and you give it a little blip to say half, and end up damned near on your a## because it actually hooked up for once. They can be dangerously abrupt off idol. Anyways, the CR cable I was refering to (from under the clutch lever to the cylinder head) is the compression release cable. Beleive it or not, your 2-stroke has a valve in the head, only opens when starting (when you pull that little lever under the clutch) to release compresssion to avoid wrecking your leg. If you kick it over, and nothing is there, and the valve seems reluctant to close, the thing may not want to run because the valve is'nt shutting at that critical first fire. If It seems to run ok once started, that could be what it is. Also, the timing could be all over the place. They have a little tendancy of shearing the itsy bitsy little key yammaha decided to use on their big flywheel, combined with plenty of vibration, things move, but will still run sparaticaly. Also watch for this on your bike : frame cracks around the upper shock mount, cracks at the bracing behind the head tube, cracks across the transfer ports (nasty, I had'em). I think this vibration thing causes a few crack problems. Anyways, how does it sound? It should rev clean and quick with no bogging. If it has any pinging at all (hope your running 90 octane or better) it could be the timing. Also, as one of the other posts mentioned, check your spark. These bikes like to eat plugs, try a new one when you check. It should be an intense blue ball with a bit of a cracking sound. How does it idol?? Are you choking it on cold start?? Does it do the same thing after it's warm??