Thank God I found this forum! I am having a problem running at high rpms. I think I have narrowed it down to a fuel restriction problem. When the motor starts to loose power, I pump the ball as fast as I can. When I do that the motor runs fine and planes out nice. What is going on here?<br /><br />I can't think of anything except a bad fuel pump, which I replaced recently but maybe it was a dud. I vented the tank and also ran from an auxiliary tank but still had the same problem so I suspect it must be the fuel pump. <br /><br />Compression is 142-145 on all 4 cylinders so that's not a problem and I just put in new plugs. Should I try opening the adjustment screws on the carbs? Someone said that might help, I just don't want to buy another fuel pump. I appreciate any advice. Thank you.<br /> 