Mc are you talking about the MG995? Or did they come out with a newer version?
As for the throttle, if you were jumping that high and hard make sure you check all the connections on the fuel lines and the exhaust. I had knocked my fuel line off one day and didnt notice it. Drove me crazy till I realized what happened. Do you have a throttle return spring on the carb? Check the throttle arm to make sure its not bent at all.
Also check you temps. If the engine was running too hot sometimes you will have a problem when you refuel. The fuel will actually start to vaporize (for lack of a better description) inside the carb if its too hot.
And where are the pictures? I wanna see this desert track.