17620-ZH7-013 17620-ZH7-023 Fuel Gas Cap Replaces Honda GX110 GX120 GX140 GX160 GX200 GX240 GX270 GX340 GX390

What It Is

This is a direct-replacement fuel gas cap for Honda GX-series small engines (GX110 through GX390). It seals the fuel tank to prevent leaks and fumes, and includes a built-in vent that allows air into the tank as fuel is consumed.

Fitment & Compatibility

• Engine models: Fits Honda GX110, GX120, GX140, GX160, GX200, GX240, GX270, GX340, GX390. Also fits many Honda-powered generators, water pumps, pressure washers, and tillers using these engines.
• OEM part numbers: Replaces Honda OEM 17620-ZH7-013 and 17620-ZH7-023. The -013 and -023 caps are functionally identical; the difference is typically a minor design or production revision.
• Thread size: 3-inch diameter, 4-thread design. Measure your tank opening—if it’s roughly 3 inches across and uses four threads, this cap is correct.
• Aftermarket: This is an aftermarket cap, not genuine Honda. It costs significantly less than OEM, but may have slightly different venting feel or plastic quality.
• Check before buying: Verify your engine’s model number (stamped on the blower housing or valve cover). Remove your old cap and visually confirm the thread count and diameter.

Key Things to Know

• Installation is trivial—just screw on by hand until snug. No tools needed.
• Vent function: If the cap feels hard to tighten or your engine runs rough after a few minutes, the vent may be sticking. Test by loosening the cap slightly while running.
• Not for all Honda engines: Does not fit GCV, GXV, or GSV series (e.g., GCV160, GXV270). Those use a different cap design.
• Durability: Some users report the vent spring or plastic can wear out faster than OEM, especially with ethanol-blended fuel. If you store your equipment outdoors, consider a genuine Honda cap for longer life.

Should You Buy It

If you need a quick, affordable fix for a leaking or missing gas cap on a GX-series engine, this is a solid choice. It’s ideal for budget-minded DIYers or as a spare for multiple machines. However, if you’re a professional using the equipment daily or want guaranteed long-term durability, the genuine Honda cap is worth the extra few dollars.