Re: Why not smaller chain?
I have been using a regular single speed bicycle chain on 2 different bikes with no problems. I Had done no mods. to sprockets & I thought the chains fit pretty nice. Less vibration & less drag. On most 2 stroke engines if you look at the output sprocket housing you can see where the 415 chain actually touches the housing at times as there are wear marks. The bicycle chain has more clearance. I also installed one on grubee 4 stroke kit & used chain idler from a tandem bike. that bike has over 800 miles with no issues.