I hope someone can help. I have an OS .91 two stroke, I can start it fine and it will idle, when I throttle it up for the first time everything is as it should be, smooth, I then idle it back down and turn it around to taxi to the runway, when I throttle it back up it quits. Do I have to have to have a pump on this or is it a matter of some other adjustment I'm over looking? I appreciate anyone's help. Thanks, Jim