My (everybody’s) first reaction  is to replace the starter — the likely culprit. But that wasn’t the remedy for the symptom.

After a lengthy run from push-to-start button to engine starter the tired aged 12 gauge wire just didn’t have the umph to reliably close the internal starter solenoid relay any more. Voltage drop. The problem was getting to be worse and worse.

The correct remedy is the depicted solenoid to send full battery voltage directly to the starters internal solenoid. A solenoid for the solenoid. Added complexity and a possible failure point? Sure, but it’s doing the job properly during engine start attempts without the dreaded “click” sound instead of cranking action. The engine starter hits perfectly each time now.

It is simply mounted to existing bolt attachment points on the back of the Yanmar 3QM30 cylinder head. The starter button delivers, but less critically, to this lightweight solenoid that was sourced from an auto parts store. The wimpy current from the start button is enough to reliably make this one.

If need be, I can also run new larger gauge cabling to ignition switch and from starting button that will better cope with the distance that voltage has to travel.  That in conjunction with this new setup would make for a truly robust system. Better than when new.

Bad hunch / wrong trail to begin with, but I’m glad to have the fresh starter as peace of mind. The original is still serviceable and can serve as spare.