hey gang... I have a little trick I use in the shop to find head or a leaky intake gaskets..... could be used near the carb too see if there is any leaks where it attaches.
and even though normaly you can hear leaks sometimes you can't and it is neat to see just how good the gasket is... you can take a mini propane tank with a hose.. while the engine is running and turn the propane on slightly.. you slowly run this around the the area.. if your engine idle increases it is the propane , due to a leaky gasket.
it works wonders on big block V8's sometimes its hard as hell to find that little bit of vacum leak and propane always seems to do a fast, safe, and clean job.
we use it in school and in my shop... you can use the colemen type or the propane torch type just unscrew the torch part and screw on a hose. if you use it for a extended time with it wide open the hose will freeze..
have fun I hope this might helpsomone.. (I was readng leaky headgasket problem post someone was asking about.)