Volvo Penta AQ211A electric choke operation

Introduction

This tutorial explains how the electric choke operates in a 1987 Volvo Penta AQ211A marine engine equipped with a Rochester 2GE carburetor. Understanding this mechanism is crucial for maintaining engine performance and ensuring smooth starts, especially in marine environments.

Step 1: Remove the Flame Arrestor

• Locate the flame arrestor on the carburetor.
• Carefully unscrew or unclip it to expose the choke mechanism beneath.
• This step is essential for observing how the choke works in action.

Step 2: Understand the Choke Mechanism

• The core of the electric choke is the thermostatic coil device.
• This coil is shaped like a spring and contains an electric heater.
• When the engine is started, the electric heater warms the coil, which unwinds, applying pressure to the choke valve to close it.

Step 3: Observe the Choke Valve Position

• After stopping the engine when it was warm, the choke valve will remain in the open position.
• Monitor the choke valve to see how it operates when the engine is started cold.

Step 4: Identify the Vacuum Braking Diaphragm

• The vacuum braking diaphragm is crucial for initial engine operation.
• When the engine starts, a vacuum is created that slightly opens the choke valve.
• This allows the engine to run smoothly for a few seconds before the choke fully warms up.

Step 5: Start the Engine

• Begin the engine to observe the choke operation.
• As the engine runs, the thermostatic coil will heat up, causing the choke valve to gradually open.
• Expect this process to take approximately one and a half to two minutes.

Step 6: Monitor Choke Valve Movement

• Watch as the choke valve opens completely as the thermostatic coil reaches its optimal temperature.
• The vacuum braking diaphragm will continue to assist in keeping the choke valve slightly open until the engine is warm.

Step 7: Adjust Idle Settings

• Once the choke valve is fully open, adjust the engine's idle settings if necessary.
• Ensuring the correct idle will contribute to better engine performance during operation.

Conclusion

In this tutorial, we covered the electric choke operation in a Volvo Penta AQ211A engine, from removing the flame arrestor to adjusting idle settings. Understanding this process allows for better engine management and smoother starts. For further maintenance, regularly check the choke mechanism and ensure the thermostatic coil is functioning correctly. Enjoy your time on the water!