The bike leaning out as it warms up might be a sign that you have an air leak. If I remember correctly, the symptom of an engine acting like it isn*t getting enough fuel as it warms up is a sign of a lean air/fuel mixture. The thought of an air leak crossed my mind. Had a similar issue with my bike once.Ended up being that bands on the carb insulators boots had all loosened up which created an air leak.