i can run it all day in dry conditions. i live on some back country roads with minimal traffic and was driving those for about 30 minutes the other day no problems. but as soon as i hit the deeper snow, then it stalls out. Its usually a 50-50 kind of deal if it restarts or not. Sometimes it restarts, but will only idle. If throttle is applied, it will die.
The quad only has 600 miles on it, so i dont think the vavles would need to be adjusted. plus they arent noisy.
Also, to clears things up, this is a Fuel Injected quad.
The last time it stalled, i towed up to the shop and checked for spark. It did have spark.