Been fighting the cravings and finally relapsed. I built a new 80cc bike just for fun. I'm on the fist tank of gas and was clocked on Photo radar going 32 MPH. Not to shabby for less than 10 miles and break in fuel.
I run the chain through the engine sprocket clockwise on top until the end of the chain hangs over the back of the back wheel sprocket.
Then I pull the bottom of the chain up to the sprocket with no tensioner in the way and get it on the sprocket and mark where to cut the chain.
You need two thin ends to put a master link on.
If the chain ends up being just right with a fat end, go a hole farther (longer) and let the tensioner handle the slack.
As for the rear fender where the chain crosses, make the fender where the chain crosses and as mention, cut a notch or bend it in there.
During the break in period u never go past 20mph, be gentle 1st 3 tanks with a 6oz per gallon the 3.5- 4oz after that. Allow everything the seat and rings to break in b4 getting on it, vidoes online please check them out. You'll get more out of it if u break it in properly