jimjeep

The throttle plate in the carb cannot move without the servo moving if you have a rod linkage and everything is attached correctly. If the engine is revving-up with the throttle plate still in the closed position then there is an air leak somewhere beyond the throttle plate. In a ported 2-stroke engine the entire case is the engines intake, so a small crack or break in a gasket anywhere will cause air to be pulled in and make the engine rev when it's not supposed to. If you think this might be the case then try running it with the WHEELS OFF at a fixed throttle position (idle or slightly higher with radio off), and use a spray can of a light oil protectant or cooking spray (this might make a little mess) to spot spray around the carb base and different spots around the engines case where an air leak could happen. CAUTION: Be careful with what you spray (and make sure it is not highly flammable) and keep a couple of large wet towels close at hand just in case of the possibility of a fire. Short spot sprays and listen for a change in engine speed. If you hear a change wait 2-3 seconds and spray the same spot again if it does it again you will have found the source of the air leak. Good Luck...[8D]