There could be several reasons why your Gixxer SF 155 BS6 model experiences a drop in RPM below 1000 and shuts off while riding at low RPM. Here are a few possible causes:
Fuel System Issues: A problem with the fuel delivery system, such as a clogged fuel filter, a malfunctioning fuel pump, or a dirty fuel injector, can cause insufficient fuel flow to the engine, resulting in a drop in RPM and stalling.
Idle Control Valve: The idle control valve, also known as an idle air control valve, helps regulate the engine's idle speed. If this valve is malfunctioning or dirty, it may not be providing the necessary airflow to maintain a stable idle, leading to RPM fluctuations and stalling.
Air Intake Issues: If there is a restriction or blockage in the air intake system, such as a clogged air filter or a problem with the intake manifold, it can disrupt the air-fuel mixture ratio and cause the engine to stall at low RPMs.
Ignition System Problems: Faulty ignition components, such as spark plugs, ignition coils, or the ignition control module, can lead to misfires or weak sparks. This can result in poor combustion, causing the engine to stall when running at low RPMs.
Throttle Position Sensor (TPS): The TPS measures the position of the throttle and provides this information to the engine control unit (ECU). If the TPS is faulty or incorrectly calibrated, it can disrupt the ECU's ability to adjust the fuel-air mixture correctly, leading to RPM fluctuations and stalling.
Engine Control Unit (ECU) Issues: A malfunctioning or improperly programmed ECU can cause various issues, including incorrect fuel injection timing, incorrect air-fuel mixture, or faulty sensor readings. These problems can result in RPM drops and engine stalling.
If you're experiencing these issues, it's recommended to have your motorcycle inspected and diagnosed by a qualified technician or take it to an authorized service center. They will be able to perform a thorough inspection, run diagnostics, and identify the specific cause of the problem.