Re: Headlight / Watts
I have a lighting system for sale in the swap and shop look for "lights". it's a almost plug and play system.
The chain on these bikes can be a pain as some are poorly made some are good I've had one chain that needed all the pins( peened you have to round over each cross pin on the chain)to keep it from coming apart. If your looking for a different roller for the tensioner I like to use a modified skate board wheel.
The defects on the cylinders are mostly cosmetic flaws and won't harm the engine as long as you don't see any black oily stuff coming out of them if you do then that is a sign that the flaw goes all the way into the cylinder wall and the seller should send you a replacement or an exchange for the bad cylinder for a good one at least replace the engine , that's my opinion on that.
I've bought flawed cylinder engines and they work just as good and one that has no casting flaws. I know it doesn't look as nice but it works just as good.
I hope I helped you guys with your questions.