I'm sure everyone knows this, but I want to throw it out there. If your throttle locks wide open, mash the rear brake and lock the wheel up. This will definately shut down the engine.
A stuck throttle always happens at worst possible time, it's hard to keep a clear head when it does. My last one happened halfway up the face of a medium table top. I set up for it ok, but when I throttled back, the bike had other ideas. It's an odd feeling taking off at full throttle when you only planned on a 1/4. I landed ok, shot across the track, over the berm, and off the track I went. Must have look like that MX Unleashed commercial. (at least thats how it felt to me) I pulled in the clutch and stopped without going down. Engine still wide open. I tried the kill switch, but it didn't work. So in my infinant wisdom, I chose to remove the plug boot. The engine did stop after that. But not before it shocked the $h1t out of me. It was such a shock, literally, that I lost my balence. You guesed it, after my graceful recovery and stop, l wound up falling anyway.
After I regained my composure, I got up enough nerve to start it up again. The bike fired up ok, idled well and shut off with the kill switch. Seemed like an odd occurance to me. I rode the rest of the day without incident. Although I was a bit gun-shy of that table top.
I have now promised myself to use the rear brake if it happenes again.
Hope this helps, Steve.
P.S. I picked up a few bottles of carb cleaner and went to town the next day, just for G.P.