old autoculto and farming machinery

All, I have the above engine fitted to one of my Monrotillers, I have the Villiers manual for the engine and another more general Villiers publication for small engine users. Neither make reference to the carburetor fitted to Monro's which has a lever throttle connected by a cable to the slide. I need to know what the right needle is and an approximate height setting for it. Having pulled the engine down over th last couple of days the valve and ignition timing are now correct, an electronic ignition module replaces the points and condensor, I have a spark and it does fire if primed with the tickler, it just will not catch and run for more than a few seconds. Any thoughts before I pull myself inside out trying to start it.

This engine was not the original but an e-bay purchase that had been set up on a stand with a small generator intended for showing, the previous owner had never had it running properly.

1968 tiller resurrected at last, narrowed the problem down to the carb for sure, built a good one from the two I had, then spent nearly a day adjusting the needle height, pulling it over and checking the plug then repeating the process until bang off it went. Dug half my plot and got the spuds in today, made up with life......

Now to start on the series 2 and finger mower!