my atv will stall out at random times. usally takes about 20-45 minutes and can get it going again. it will act like it runs out of gas even when its full. it will usally start with the choke on even when the motor is warm, but when I try to push choke in, it dies.. this goes on a few times till it starts running again… I use 89 or 93 gas ONLY. completely stumped…