X300 will not crank

My X300 will not crank. Can turn on ignition switch and the lights come on. Used jumper cables and jumped straight to solenoid and after a couple cranks fired right up and runs, with me not setting on seat. Mower will engage and continue to run fine.

What could be going on? A bad safety cut out switch? Fuse maybe? Thanks for any input.

Mower wiring 101
Power usually goes from the hot side of the starter solenoid .
1) through a fuse
2) the the B ( = battery) terminal on the ignition switch ( tiny numbers under the switch )
3) to S (= Start) terminal on the switch
4) the the PTO switch or PTO safety switch on manual PTO's
5) to the brake safety switch
6) to the trigger wire on the solenoid.
This is a daisy chain so a break anywhere = no cranking
If the solenoid has only 1 small wire then the ground is via the case which will benefit from a clean where it contacts the body of the mower to get a good contact.

The ignition control can either be on the key switch
M + G = off
or on the throttle plate.
follow the thin wire from the coil
This is a ground wire.
Ground = off
Open circuit = on

Note the seat switch is not in the above.
On tractor style mowers the seat switch IS NOT IN THE CRANKING CIRCUIT.

Thanks for the electrical flow. Time to brake out the multimeter.

I use a test lamp as it is a works or doesn't work case and numbers just confuse people.
Apart from that a test lamp can be clamped to one so you just a have a probe in one hand and the other free to work switches .