I can't really think of anything that would produce a clicking sound from your carburetor. And I haven't even worked on a carbureter for quite some time. But I'll try to give you a couple places to begin looking.
When you experience a mysterious shut off of your engine after a few short minutes of operation, it's almost always a spark, or fuel related problem.
As for spark, your coil could be going bad. (Internal wires are broken/shorted) What happens is, while the engine compartment is cold, the coil will work properly, but as the engine runs, the radiant heat, combined with the heat of the coils normal operation will be enough to separate the internal windings or short them out. And it will stop functioning until it cools down.
As for your fuel system, you could be experiencing a host of problems. Your fuel lines could be experiencing "Vapor lock". Which happens when your lines build up too much heat and it boils the fuel.
You could have a sticking float/needle assembly, which won't be able to keep up with your motor's fuel demands. (Choking it off)
Your fuel pump could be failing, your fuel filter could be clogged, or your carburetor may have an internal passage that's clogged.
There's so many things that could go wrong with a carburetor r and cause your described symptoms s. That's why fuel injection was invented!
The first thing for you to check is your ignition system. Once you can eliminate that, then look into your fuel system, starting with the simple stuff.
With 120K plus miles, it may be time for a cab rebuild anyway.
Monday, January 11th, 2010 AT 8:39 PM