When you move throttle there is a nice(immediate) steady stream of gas? float level is correct(at bottom of sight plug) What jets are in there? Are your end carbs are vacuum activated? Suggestions (1) disconnect/plug the vac hoses to the end carbs to isolate them from the center carb so we can concentrate on fixing the one center primary carb & (2) richen up the center carb jets 4-6 sizes & see what happens. Holler back when you can. PS I am not sure if plugging the vac lines is needed or will help us but I do want to isolate the center carb to narrow down where the problem is & for sure richen up the center carb for a tryout. Almost forgot what do your plugs look like?

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