Hello Katzohki,
If ya do a search, their is a lot of info on the rear sprocket. I put my 66cc Skyhawk on a beach cruiser (coaster brake) and had to modify the rear sprocket, otherwise I couldn't fit both spacers correctly behind it. The sprocket did not fit over the coaster break bearing cup. At first, I tried it without one spacer, but the chain kept comming off.
So I had to take a grinder and open the hole until it fit over the cup, then I could fit the second spacer behind the sprocket. Works like a charm.
What kinda bike ya putting it on?
Best advice I can give you is replace all the nuts that come with the kit for lock nuts. Plus, thread locker is your best friend
Use it on EVERYTHING! Otherwise you will ride your bike for several miles then notice something is comming loose. No fun.
I'm in the process of waiting on parts. I plan on rebuilding mine and going for a 150 mile trip. I would like to ride to bike week in Laconia NH, and show off my build. Gonna be an adventure !
I built the bike last summer and learned the hard way on what works and what does not. This site is the holy grail for info. I just signed up a couple of weeks ago myself.
Have fun