Turning the key to "off" OR pulling the kill cord have the same effect. They connect a wire (white, as I recall) to ground. As both seem to have failed its unlikely that is a problem with the switch in the control box. You need to test for continuity between the switch and where it goes in the engine. If it were mine the first thing I would check it the "multiway" connector plug that couples the 703 to the engine. If you take the control box to pieces beware that it can be a bugger to get all back together again!
Yep, second Pol on all of that - I had the same thing on mine a couple of years ago - was one of the bullet connectors inside the 703.
And beware- the screws that hold the box together have an annoying habbit of snapping when you try to undo them, so if it's not your loom connector, use a LOT of your favourirte "release juice" before opening! (the cast threads on the case are spigots, so heat is as good as useless)
