old kawasaki suffer with ignition switches getting hot from exhaust and engine heat . this allows the wires/contacts in the rear of the switch to move and lose contact . my old zzr took it one level further and the contact point was so loose it fell out and cut the power in 3rd lane m4 ... i had been struggling with hot starts prior to this and tried everything feasible ..ie valve cleaeances , carb balance new.plugs , battery etcetc after replacing the switch unit i had no further issues ( i had a temporary toggle switch system until i sourced a reasonable ignition switch unit ) which made me realise that i had no problems starting when hot . only problem was i did once get so complacent with this system i just get on the bike start off and then realise i had not put the key in to disengage the steering lock ... and i had a pillion on board .we both ended up on the floor .Lesson learnt . remove the lower section of switch( bit with wires) ( no need to undo the tamper bolts ) look at the wire to contact mounts and see if they rotate in the mouldings .