Insufficient Fuel supply accounts for 37% of the causes of faults. When the output pressure of the Fuel Pump is 15% lower than the standard value, the engine will stall when the throttle opening is more than 70%. The measured data shows that the flow rate of the faulty fuel pump drops sharply by 40% at 4000rpm (for example, the normal flow rate of the Honda CBR500R should be 60L/h, but it is only 36L/h when abnormal), causing the air-fuel ratio to deteriorate from 14.7:1 to 18:1, which is 10% beyond the correction range of the ECU. A typical case was seen in the 2023 Isle of Man TT race. A modified motorcycle suffered a 75% clogging of the fuel pump filter, causing the pressure to drop from 4.1Bar to 2.3Bar during acceleration, which increased the probability of power interruption at the end of the straight by 60%.

An abnormal ignition system caused 32% of the engine to stall during acceleration. An increase of 0.2mm in the spark plug gap will lead to a 30% increase in the breakdown voltage demand, and the misfire rate can be as high as 20% when the throttle is fully open. Industry statistics show that insulation aging of high-voltage packs can cause a 35% attenuation in secondary voltage output (the normal value should be ≥25kV). For instance, the frequency of engine stalling of the Yamaha R3 model increases by three times at 6000rpm. Kawasaki’s Technical Bulletin confirmed that when the ignition coil resistance deviation exceeds 15% in a high-temperature environment (≥38℃), the engine power drops by 18% and the 0-100km/h acceleration time is extended by 2.4 seconds.

The imbalance of air-fuel ratio accounts for 25% of the faults. When the response delay of the oxygen sensor exceeds 300ms, the error of the fuel correction amount of the ECU reaches ±25%, triggering the sudden acceleration fuel cut-off protection. Real vehicle tests show that the voltage drift of the throttle position sensor by 0.15V (the standard value within the linear range of 0.5-4.5V) will cause a 22% deviation in the calculation of the fuel injection pulse width. According to the BMW locomotive diagnosis report, in areas above 2,000 meters in altitude, due to changes in atmospheric pressure, uncorrected ECU parameters will reduce the mixture concentration by 12% and increase the probability of engine stalling by 40%.

Multi-system coupling faults require comprehensive diagnosis. Vacuum tube leakage causes the intake pressure to fluctuate by ±10kPa (the normal value is ±2kPa), and when combined with abnormal fuel pump pressure, the probability of engine stalling doubles. Harley-davidson maintenance cases show that the blockage of the vent pipe causes the negative pressure of the fuel tank to reach -15 kpa, reduces the fuel pump’s fuel delivery efficiency by 50%, and the frequency of engine stalling at a constant speed of 80km/h reaches 8 times per hour. During the Southeast Asian hot and humid monsoon in 2024, the failure rate of this type increased by 45% year-on-year. Due to the high-temperature and high-humidity environment accelerating the aging of rubber parts, the median maintenance cost reached 1,200 yuan.

Preventive maintenance can reduce the risk by 85%. Regularly clean the fuel injectors to keep the flow deviation within ±3% (as required by the national standard GB18285-2018), and shorten the fuel pressure test cycle to once every six months. The Ducati maintenance manual confirms that replacing the gasoline filter every 8,000 kilometers can extend the fuel pump’s lifespan from 30,000 kilometers to 50,000 kilometers, saving 60% of the replacement cost. The fleet operation data shows that after the implementation of OBD real-time monitoring, the acceleration stall failure rate has dropped from 22% to 3%, and the maintenance budget per 10,000 kilometers has decreased by 1,500 yuan.