DAVE R. - Like Gerry said, without an "Accelerator pump" carbs have a hard time going from slow idle to high RPM or full load. Whether a carb is run with a governor or not really doesn't make that much difference. I know some of the governors on Ford truck engines were pretty complex. Truck governors are much different than tractor or industrial engines, they just restrict max. RPM, they do not maintain a set RPM.
I was never much of a fan of just shooting a stream of raw gas down the intake tracts of engines like accelerator pumps do. But it works.
The article in Cycle Mag. I mentioned by Gordon Jennings explained how each adjustment of the different metering systems on the Mukuni works. As Gerry, said, the slide type carb also used metering needles & jets, the idea was to try to keep air velocity up as fast as possible over the air bleeds in the carb body. The needles & jets, cut-away on the front side of the throttle slide, and if I remember correctly the adjustment screws for idle & high end controlled air and not fuel.
They're not impossible to put a governor on, just not easy.
To keep this On topic, I did the 5-minute welding job on the 38" deck for the 72 yesterday & installed the deck. The 72 did NOT want to start as quickly as I thought it should after sitting since Nov. 8th, SIX months! It didn't fire & run until the THIRD revolution. Normally fires on the second. Guess I better plan on a tune-up.
Couple weeks ago we discussed different ways to "sharpen mower blades". Steve B suggested using a BELT SANDER. I tried it....did work good. Much easier to keep the cutting edge Straight! THANKS for the tip Steve!