After riding your motorcycle at a given speed for a shorter or longer period, you close the throttle and pull the clutch to let the bike roll - and then the engine dies instead of maintaining a steady idle. If you have a quiet engine, you may not notice this before you release the clutch and open the throttle again, and you are in for a nasty surprise when the rear wheel locks up. What will cause the engine to stall when you close the throttle ? This issue is rarely caused by ignition problems, so we are looking for fuel supply issues or mechanical problems: - Air/Fuel ratio too lean (The engine may not have problem in colder weather when the air density is high and the engine have more power, but on a hot day the engine will be weaker and may stall) - Poor fuel map - Leaking intake rubber hoses between throttle valve housing and cylinder head - Throttle valves not correctly synced - Throttle position sensor (TPS) not correctly adjusted - Valve clearances are too tight - Low compression. |