I've just rebuilt my pulsar and when i start it from cold it idled really low like its going to cut out then it picks up to 1200rpm then once its warn it idles at 900rpm normal but when I rev the engine up it goes to around 200rpm struggles for a sec then dies. I start it straight back up and it idles back to 900rpm no props.anyone got any ideas as its really winding me up, cheers