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TECH FEA

Technical features and description

Knock control In knock control, the engine ECM receives the knock signal from the knock sensor which is installed on the cylinder block between the cylinder banks. The engine ECM retards the ignition timing and decreases the engine speed according to the amount of knocking to protect the engine from damage. If the knocking occurs frequently, the ignition timing is retarded until the knocking is no longer detected, and the retarded ignition timing is maintained, using the learning function. The knock control activates according to the following conditions: Engine temperature Engine speed Less than 4500 r/min

4500 r/min or more

Less than 20 °C (68 °F) Knock control does not activate

20–25 °C (68–77 °F) Knock control activates if conditions continue for 0.5 seconds Knock control activates

More than 25 °C (77 °F) Knock control activates

The knock control also activates when the engine temperature sensor is malfunctioning regardless of the preceding conditions.

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2011 YAMAHA F225CA 4-STROKE OUTBOARD Service Repair Manual SN:1000001 and up  
2011 YAMAHA F225CA 4-STROKE OUTBOARD Service Repair Manual SN:1000001 and up  
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