Hi All. I have an issue with my eliminator 125 when it is running. It starts fine, runs on tick-over and for about 3 seconds when I turn the throttle. After that it starts to pulse from idle speed to about 2k revs, even when the throttle is held open and still. If i stop and restart the bike it will repeat this action over and over. It has been fully serviced, replacement plug and had the carburetor cleaned out twice. Any ideas?