the encarwi carb is a simple carb to clean our. make sure the reeds are clean and seated properly. there is also a service limit on the reeds, i think its .005" or so, i'd have to look thru my shop manuals. you need to have about 120 lbs of compression. make sure the decompression valve is sealing. also check for spark and inspect your plug as joe suggested. another good thing to look at is the exhaust port and pipe. make sure they are clean. that engine wont run without the air box either. make sure its on tight. there is a service manual for this engine at www.mopedriders.org in the moped repair section.