Klr just stopped

[etboy]

I posted something like this in another thread, as it appeared to be the same problem, unfortunately no one came up with a solution, so I'm going to post this hoping that someone can come to my rescue.
The problem started several thousand miles ago in Peru. I noticed that gas was leaking from my petcock & a local mechanic fixed it & I was good to go. A couple of hundred miles later the same/similar problem occurred, again another mechanic did something or other to it & I was good to go for another thousand miles or so. It then happened again as I was climbing up to 7-8000' only this time it wouldn't start. I stripped the carb, though everything seemed spotless, changed the main & the pilot jets, but still no go. Got it towed to a mechanic who replaced the carb, and everything was hunky-dory, up until yesterday. I was at the end of a 300 mile day, as I got into stop & go traffic it started again, coughing & spluttering & eventually dying. I left it for 45' or so to let it cool down, then it started back up again? I would add, that before, the problem mainly occurred (Though not exclusively) when I was at altitude, this time however, I was descending. The weather was hot, but the engine was nowhere near red lining.
I am beyond concerned now, as I am heading into deepest Patagonia shortly, where ditching the bike will probably be the only alternative. Obviously something I do not want to do, as we've been through a nearly 2 year ride down from San Diego. If anyone has any ideas, I surely would appreciate any advice. Cheers Y'all. Tony