16620-Z8D-305 Thermo Wax Assembly & 16600-Z8B-900 Choke Control for Honda

Key Features

• Regulates engine choke position based on thermal expansion to ensure proper cold-start fuel-to-air ratios.
• Maintains consistent automatic choke operation to assist with engine ignition and warm-up.
• Includes integrated fuel shut-off valve to prevent fuel flow during storage or transport.
• Constructed from heat-resistant materials designed to withstand engine compartment temperatures.

Replaces / Cross-Reference Part Numbers

• Thermo Wax Assembly: 16620-Z8D-305, 16620-Z8D-841, 16620-Z8D-842, 16620-Z9L-003
• Choke Control Assembly: 16600-Z8B-900
• Fuel Shut-Off Valve: 16950-Z0Y-003

Compatibility & Fitment

• Fits Honda GCV160, GCV160A0, GCV160LA0, and GCV190 engine series.
• Compatible with Honda lawn mower models including, but not limited to, HRR216, HRS216, and HRX217 series.

When to Replace

• Engine fails to start or remains difficult to start when cold.
• Engine experiences rough idling or stalls shortly after ignition.
• Choke plate fails to open or close fully as the engine reaches operating temperature.
• Visible damage, melting, or seizing of the thermo wax plunger.
• Leaking or stiff operation of the fuel shut-off valve.

Installation Tips

• Allow the engine to cool completely before beginning the installation.
• Document or photograph the routing of the choke linkage and cable before removal to ensure accurate reassembly.
• Ensure the thermo wax element is properly seated within the choke control housing to allow for correct thermal expansion.
• Verify that the choke plate moves freely without binding after the new components are installed.
• Always check for fuel leaks at the shut-off valve connection after installation and before operating the engine.