Bit of a surprise this morning. I got up early, and thought "I wonder now that everything is working so well, if I should try the larger carburetor again."--You see, that bore of carb works just fine on the Odds and Ends engine which has the same 7/8" cylinder bore. I removed the small carb and put the large carb back on,---and after opening up the needle valve a couple of turns, the engine started up and runs just as well as it did with the smaller carb I built. I don't have any really good explanation for this. I did discover that there was some crud in my fuel tank that was obstructing the fuel flow sometimes, and had cleaned out the tank at some point during the build. It is possible that what I seen as fuel starvation with the large bore carb was simply the fuel line being blocked by crud in the tank. Oh well, all's well that ends well. Now I have a spare carburetor.----Brian