My 1978 model has stalls after a minute at full throttle. I tried injecting carb cleaner into each carb. The top two when injected almost stalled out the motor. The lower one made no difference in rpm's when injected. Could this be a teltale that it is not operating? I have change tanks,hoses and cleaned fileters and bowls but to no avail. <br /><br />Bchappy
