What is the typical symptom of a motorcycle engine running with an excessively lean air-fuel mixture?

1. Engine overheating, popping noises on deceleration (lean pop), and hesitation or flat spots during acceleration.
2. Heavy black smoke from the exhaust, spark plug fouling, and engine bogging at high speed.
3. Wet oil on the spark plug electrode and blue smoke from the exhaust.
4. The clutch slipping under load and the transmission popping out of gear.