When you pull the choke out at idle and slow speed the atv will load up and quit. I know this is normal. But shouldn`t pulling the choke out at half to full throttle do the same thing? Atv has a high speed miss like starving for gas and pulling the choke out does nothing when it happens. Shouldn`t it try to load up and quit at high speed also?

 

No,engines will not always choke down at high speeds as the engine is turning over fast enough to accept an extra gulp of fuel when you open the choke circuit. At an idle,then yes most times will cause one to choke down because it can't take this load of fuel all at once. The problem you're having may not be fuel or carb related,but could be electrical if fuel, carb,air filter ,etc have been eliminated. Ignition could be limiting or shorting at high speeds.Doesn't work all the time,but a simple timing light hooked up to the plug then rev the engine and hold at a high speed. The light should be a continuous beam,but if problem is ignition related,the light will mimic the engine and be intermittent just like the miss. First thing you could do though is to pull the black wire from the reverse limiter. If this doesn't help,then clean the pulse coil and flywheel area. If still doesn't help then checking resistance readings on stator and the coil may help. Fuel that has water contamination can do the same thing and act like it's limiting at high speed as it sucks water from the very bottom of the carb and sputters.