I believe I have the same engine as you and mine developed the same problem shortly after I installed it. It was a new engine.
Have someone at the control panel
, with the ignition on but engine NOT running. Put your ear by the fuel pump
and have your assistant push the stop button a couple of times. If you can hear a "click" sound - then gently slip the rubber boot off the solenoid and clean & lubricate the actuator shaft the solenoid. All I needed was a paper towel and a teflon spray lubricant. Problem was solved
in less than five minutes.
The engine had less than 100 hrs when the problem occured and the above technique has solved
it for the past 1700 hrs' usage.
Charlie - I've been lead to believe that your alternator
diodes will be destroyed immediately if the ignition is switched off while the engine is running... is this not the case with your engine?