First when you jump the solenoid do you have the key in to run position? Second have you checked the fuel solenoid? Third when you say it will not start, do you mean nothing happens or engine spins but no firing in the cylinders?
Just found out on my mower, which had same problem, that the nut holding brake rocker on was loose and not making contact with safety plunger, tighten nut up and all is good.
