I have the GS SUT truggy and I dunno, Since the last rebuild it's acting funny. The high end RPM runs fine, but the low end is very wierd. It's hard to keep it running and when you accelerate you can hear the engine wind up but its not steady. I'm sure the low end mixture is messed up but the symptons point at something different. The engine is slow to rev to the top end. I dunno. please help