Engine chain falls off

Chain tension and alignment is critical. If you're using a chain tensioner make sure it is aligned with the chain path. All of them need a slight twist to get the tensioner wheel to align with the chain. The tension is also important. Shoot for 1/2 to 3/4" slack in the chain measured on the top chain before it enters the engine, clutch engaged and bike rolled forward so the top chain is loose. Adjust the tensioner, if you're using one, so you have the recommended 1/2 to 3/4" of slack. Try these and get back to us with the results. Rear sprocket concentricity is also critical. Is your sprocket exactly centered on the rear hub? It has to be to keep the chain from bouncing. There is a lot of good information here on centering the rear sprocket but if you need help just ask.
Tom

Your problem is in the throttle linkage as explained in your other post. Check there for some help. As far as wiring, here is a diagram that might help. Keep in mind that wire colors are not the same from kit to kit. Some are yellow and green, some red and green, or yellow but most engines have a blue, black and white from the magneto. The kill switch wiring can be done two ways. See the diagram below.
Tom

Son,
I'm chasing your problem from post to post. You'll need to keep your questions in one area so we can help you. Check your other question for an explanation and maybe some help. Your photo shows the throttle cable, that's not a wire. There is no connection between the kill switch wiring and the throttle cable. They are totally seperate items. There are two 'Wires' from the kill switch and one 'Cable' from the twist grip throttle assembly. Did you confirm that the slots in the barrel shaped device on the end of the 'Cable' are as I described? Long slot on the right, short slot to the left. And did you check that the barrel, or slide, moved up and down when you twist the throttle? It is easy and possible to install the slide backwards which will result in the problem you described in your previous post...no idle. Hope this helps. We'll get you going. Don't fret.
Tom
Tom