I have a 85 Honda 250sx that I recently picked up. It was running but it just died and has no spark at all. I did replace the cdi box,coil and the pickup coil all new parts. It still does not have spark. I even disconnected kill and ignition switch. Any ideas as to what could be the problem

 

Trouble with substitution is you can introduce a fault it didn't have to start with. Test every component of the ignition system. Assuming the ignition is the same as the 4 wheeler, the exciter coil in the alternator should produce AC voltage when engine is spun. The trigger coil should do the same. The earth lead to the CDI should be earthed (almost certain to be a green wire). The kill wire from CDI should be earthed when ignition switch is off, and open circuit with ignition on. (Could be other way round). If there is a wire from neutral indicator to CDI, it must be earthed in neutral and open circuit in any other gear, (again could be opposite way round). The wires to the ignition coil should produce a high AC voltage when engine is spun if everything else tests out as OK.