Yeah, that site on generators gave me some ideas, but with that carb (tecumseh 4 stroke mower/generators) it does something different than the HT carb.
The fuel on those is not metered by a needle, but is controlled by the amount of air that passes over the jet. With pressurized gas, that jet kit just sends it through behind the butterfly valve, which is why they need the vacuum operated regulator. Also, generators undergo very sudden high loads, and aren't controlled by a hand throttle. Plus, generators may be left unattended and could stall, so it needs a gas shutoff automatically. On a bike, you could just restart or turn off the fuel.
On these one note charlie MB bikes, you can probably just let the motor get extra fuel at idle, to keep up with its hard running throttle settings or WOT.
I'll mess around with it some probably this summer, maybe sooner. If it runs ok and seems practical, I'll post a thread about it with steps and photos.
Meanwhile I'll read on and see if someone beats me to it. Good Luck and Happy New Year. I am having lots of fun with this website.
PS I like lawn mower tinkering too, esp as it relates to lawnmower engines on go karts (or rarely, motor bicycles and trikes).
I am wondering if anybody has put a HT slide type carburetor or similar, on a 4-5hp lawnmower, to use a BMX or V brake lever. Lots of hinged cheap brake levers are on bike shop sites.