im working on a old cat 20 crawler, i have a kit for the carb but what i am trying to find is a diagram of it showing the parts, and what they do,ive got the initial settings from the cat manual i have, but thats as far as it goes, for instance there is a small plunger on the square bowl if this was a diesel this would be like on top of the fuel filter housing to fill and bleed the filter, is that what this does? if not what, it took me most of a day to replace the throttle blade bushings, those suckers were stuck! as well as being egg shaped where the shaft goes thru them any help would be appreciated, ive looked online but i cant find that style of updraft carb, the carb number is agl 364072