Take hand held propane torch and remove burner from end of brass pipe.

Slip 24" of vac hose over brass torch pipe.

Tape free end of hose to 24" long coathanger wire.

Crack torch valve to where you hear slight hiss at end of hose, then using wire, fish hose end all around intake sealing flange....Bend wire to reach under and behind stuff.

When you get near the vac leak, the engine will smooth out.