Hi everyone, does anyone know where I can find a kit like this? The guys who developed them - seemingly in partnership with B&S, are called Propane Power Systems (https://www.propanepowersystems.com/). I do not see it for sale anywhere for the twin Vanguard, although the single cylinder versions are easy to find.
You might also note that my Vanguard starter failed after 1 year (about 40 hrs of run-time with 1 start per wk). GenSpring has the starters specially rebuilt rather than trust the new B&S starters.