I am baffled. When the engine is cold, (manual choke off), the motor runs great for 2 minutes or even 20 minutes, as long as I do not throttle back to idle. Once I throttle back and then try to accelerate again, I have no mid range and the engine quits. Starts great, and idle is normal. Sometimes if I just gun it immediately to full throttle, it will catch and not stall and it runs okay until I reduce power again. If I let it cool down and start all over, it runs great at high power until I make that first power reduction and then I am dead in the water again. Spark tests okay, new fuel, fuel line, cleaned carbs and filter. What now?
