KDXRIDER.NET

Reed valve has an arrow on it, is the arrow supposed to tell me which way to put it in?

Not sure on arrow ,but the rounded tab (A) on the cage should be on the lower left side of the engine/bike.

Here ya go. Lower pic.

If you put it in wrong, you'll be able to tell:

Mine has an arrow on the metal piece that if you put it in one way it faces down and if you flip it up and put it in it will point up. It'll go in either way. Also my o rings are worn out on the head pipe could that prevent it from running? Oil was coming out pretty significantly

No if the pipe was missing it would still start.

Probably fouled the plug try a new plug