NHTSA Complaint #11678946 — 2023 SUZUKI GSX-S1000

I am submitting a formal complaint regarding a stalling issue with my 2023 Suzuki GSX-S1000GT+. Issue Summary: The motorcycle starts normally when cold. However, once I begin riding and pull in the clutch to stop (such as at a stop sign or traffic light), the engine stalls unexpectedly. The stalling occurs intermittently during this phase and continues until the engine reaches full operating temperature. At that point, the issue no longer occurs. When the engine stalls and I attempt to restart it, it will not restart unless I apply throttle manually. Simply pressing the starter without throttle input results in a no-start condition. Key Observations: Cold Start: Starts up as designed. Initial Riding Phase: Engine stalls when pulling in the clutch to stop. Restart Difficulty: Engine will not restart unless throttle is applied manually. Post Warm-Up: Once at operating temperature, the issue is no longer present. Performance: The motorcycle runs smoothly under load and throttle aside from this stalling condition. Diagnostics: No DTCs are stored and no check engine light is illuminated. Safety Concern: This issue poses a serious safety risk. The stalling is intermittent and unpredictable, which can leave the motorcycle incapacitated in traffic or at intersections. This creates a hazardous situation for the rider, especially when the engine fails to restart without applying throttle—a detail that could easily be overlooked during a critical moment. Technical Assessment: Based on my professional experience, this appears to be a calibration or software logic issue rather than a component failure. The ECU does not seem to manage throttle plate position or idle control properly during transitional warm-up phases. As the motorcycle accumulates mileage, the issue has become more noticeable, suggesting a drift in adaptive values or insufficient compensation in the ECU’s warm-up strategy.