I have a jonway zuma clone 150cc gy6. It had 145 miles on it. When I am going about 40mph and then twist the throttle all the way it starts accelerating then it makes a pop pop noise and slowly slows down, if i let off the throttle then twist it again it accelerates fine. Seems to be a intermittent problem, top speed was about 58 now 52 mph then it pops and slows down to 45moh/ It idles fines and starts great. I'm thinking its either carb related or a bad CDI? It wouldn't be valves cause its intermittent and idles fine right? HELP!
