John's musings are the reason that I also carefully do the unlit propane-torch tests on ALL connections leading-to, coming-from, and connected-to the carburetor on a low-revving/idling running engine (as nicely described by Carl).
For what it is worth, I also use a lit propane torch to beautifully sear/brown the outside of rare steaks and of tastey sliced grilled oiled vegetables (the torch adds wonderful browning control).
