Hi All. Am new to this forum, thanks in advance for having me! I just picked up a Super 8 150 for the wife. Its a 2013 with 800 miles on it. It ran rough right and was hard to start from the get go taking it home from the guy I purchased it from but for $400 figured I could drop a couple of bucks and get it running. I pulled the spark plug and was jet black running rich I assumed. I checked the valves which were spot on. So pulled off the air cleaner assembly, cleaned up the spark plug and plugged the spark plug back in, leaving the air cleaner off. So now the scooter is firing right up no problem and running better, (just minor albeit annoying backfiring), except when I try to get over 40mph and it then loses power and bogs done, until it settles back in under 40mp. If I keep it under 40 it runs okay with some backfiring on de-aceleration. Maybe the electric choke or wrong jets, carb needs cleaning or new carb? Thanks in advance for any help!