hi if like me you have your timing set at 20 degrees btdc @ 1000 rpm on your cross flow, it can be a bit of a strain on the starter to swing the motor, this device retards the timing by 7 degrees for easier starting, as soon as it fires up let go of the cable knob and it reverts back to the correct running setting. this type of gizmo was fitted on bikes years ago. check davef photo archive.