Yamaha F200B Service Manual

Also see for F200B: Rigging guide Owner's manual Owner's manual

2-7TECHFEA Technical features and descriptionKnock controlIn knock control, the engine ECM receives the knock signal from the knock sensor, which isinstalled on the cylinder block between the cylinder banks. The engine ECM retards the ignition tim-ing and decreases the engine speed according to the amount of knocking to protect the engine fromdamage.If the knocking occurs frequently, the ignition timing is retarded until the knocking is no longerdetected, and the retarded ignition timing is maintained.Also, a learning function for the knock control has been adopted.The knock control activates according to the following conditions:The knock control also activates when the engine temperature sensor is malfunctioning regardlessof the preceding conditions.EnginetemperatureEngine speedLess than 20 °C(68 °F) 20–25 °C (68–77 °F) More than 25 °C(77 °F)Less than 4500 r/min Knock control doesnot activateKnock controlactivates if conditionscontinue for 0.5secondKnock controlactivates4500 r/min or more Knock controlactivates