Sorry to hear about your troubles. They can be a fickle beast until you figure it out the magic.

Have you ever heard this Zilla run before? 

Try this sequence:
1. Key or Ignition OFF
2. Choke on
3. 3-4 Primer Kicks (don't have to be hard)   
4. Key or Ignition ON
5. Cycle kick lever to the hard spot
6. Give it a hard kick!

This works for both my 500's like magic. If that isn't doing it, then we'll have to dig deeper.