Releasing the clutch quickly while the motorcycle is in neutral gear generally does not cause any damage to the engine. When the motorcycle is in neutral, the transmission is disengaged from the engine, and the power from the engine is not transferred to the wheels.
It's always advisable to exercise caution and follow proper clutch control techniques. When releasing the clutch, it's best to do it gradually and smoothly while in gear, allowing the engine and transmission to engage smoothly and transfer power to the wheels without sudden jerks or excessive strain on the components.
If you accidentally release the clutch too quickly while in gear, you may experience a sudden jolt or stalling of the engine, but it's unlikely to cause severe damage unless it becomes a repeated habit. However, repeated harsh engagement or disengagement of the clutch can lead to premature wear and tear of the clutch components over time.
To ensure the longevity and smooth operation of your motorcycle's drivetrain, it's important to practice proper clutch control techniques and be mindful of how you engage and release the clutch when riding.