Drives - then dies... Increasing RPM - then Decreasing.

[Winther]

Hi there guys - I'm new on this forum, looks nice. I so hope you can help, im jammed without transportation and miss driving my gs500.

First of all, I'm no mechanic, just knows how to take the things apart and more or less how a carburettor should work and so on - so bear over with me.

Heres the problem, a couple of weeks ago my bike died on me, and after alot of carburettor checking we took off the shield to the timing and found out the problem was that the screws had vibrated lose in there. After putting in the screws the bike fired right up, and to me it seemed like it had alot more power suddenly (maybe im just imagining though). (im telling you this, because it might be related - I wouldnt know)

But, sadly, 2 days after, my bike dies on me again, but in a very characteristic way - I was driving (a lil hard I admit) and the bike suddenly starts decreasing rpm the more I turn the throttle, I then stop and finds out that if I turn the throttle a little bit then rpm increases, but above a certain point it starts decreasing and almost dying on me. To make a long story short: It finally died on me, I got it started with same problem and it died on me several times.

I've taken apart the carburettor again, since the problem to me would indicate bad mixture or something, but everything looked right in there. The air filter is not clogged, the spark plugs looks good (even though a bit more carbon on them than last time I had em out - but think thats a biproduct of the problem and not the cause).
I then put together the carburettor again, and it worked, with all the power it should. And I drive off happily, but after a mile the problem appears again and it dies.  I checked the fuel in the carb-drain looked clean and water-free, so not the fuel.... Now I have no idea what it could be - HELP please.

Symptoms:
- Increasing then decreasing rpm by throttle turn and normally eventually dying.
- I think the engine seemed hotter than it usually does, it IS summer in florida now, but still shouldn't change that much. (I have sufficient oil on it)
- Won't start anymore now.

Hope you guys can diagnostice this better than me  - Im in such a jam right now.