I was driving my scooter about 35-40 MPH and all of the sudden my muffler started to make a much lower-toned sound that immediately got my attention while still accelerating and driving like normal. I came to a red light and pulled my scooter all the way to the right side as my muffler was still projecting a much lower-toned sound than usual. Upon a complete stop my scooter died and I have not been able to start it back up. I just (2 weeks ago) spend $287 fixing it with a new battery, cleaned out carburetor, and other general maintenance. It worked perfectly fine for those two weeks and then the above-described situation happened. ANY SUGGESTIONS?