Ted, I did have issues with wierd RPM readings on a Wren when the glow plug wires were run along side
the starter & RPM sensor wires. A friend had a Wren 44 which used a 'wand' to start it but quickly changed
to an on-board starter with FOD screen after the rubber insert fell out of the wand fell out & narrowly missed
getting sucked into the intake. A clutch is needed on the starter motor shaft if mounted on the engine.