I’m sure you would have probably noticed if the engine was sliding back, but is the engine sliding back? I forgot to set my engine stop once and after a few laps it began to pull itself back under acceleration, which of course pulled the throttle open. Very unnerving to have your kart develop a mind of its own and go full throttle when you aren’t demanding it. Double check and make sure your mount is tight and the stop bolt is set.
Probably not your issue, since it does not really fit the symptoms… but does not hurt to check :)
2010 Spirit [Birel] SP32 // SRS CR125 - Stock Honda [#08]
Hill Country Kart Club - New Braunfels, Texas - http://daledaugherty.wordpress.com/