If anybody has the Huasheng 49cc 4 stroke engine with the 415 chain, change it!!!! My chain went bad over the weekend, went to Tractor Supply to get a new one, opted for the 41 chain. I thought the gear reduction box (trans?) was the reason for all the noise when riding around. Was I wrong.. It is much quiter with this chain. I also noticed way more power!! The 415 chain robs you of much needed hp. While riding in my subdivision on my hills, with the old chain I could climb the hills without pedaling, but I could feel the engine laboring. Now I climb the hills like I shaved a 100 lbs. I know I can go with a smaller sprocket for more top end speed, and still be able to handle my hills. So I am excited to order my new sprocket today. OH also I can now pedal the bike since there is much less resistance. Not too important unless you brake down. Anybody else like to chime in on the 41 chain upgrade?