The Honda GX160 typically uses a standard NGK spark plug with a 14 mm thread, most commonly the NGK BPR5ES, gapped at about 0.028–0.031 inches (roughly 0.7–0.8 mm). Some GX160 variants or regional models may use a closely related plug such as BR6ES. Always verify the exact specification in your owner's manual or on the engine label.
Recommended spark plugs for the GX160
These options cover the most common GX160 configurations. If the exact model number or regional spec differs, choose a plug with the same thread size (14 mm) and a similar heat range, and set the gap to the guidelines below.
- NGK BPR5ES — 14 mm thread, 0.028–0.031 in gap; widely recommended for GX160 engines.
- NGK BR6ES — 14 mm thread, 0.028–0.031 in gap; another commonly used option when BPR5ES is not available.
Concluding note: If you cannot source these exact models, look for an NGK spark plug with a 14 mm thread and a gap of 0.028–0.031 inches, with a similar heat range suitable for small 4-stroke engines, and follow your manual for any region-specific recommendations.
Why heat range matters
The GX160’s performance, fuel efficiency, and plug life depend on choosing a heat range appropriate to your operating conditions. In general, smaller engines running hotter or under heavy load benefit from a slightly cooler plug, while engines in cooler climates or light-duty use may run better with a hotter plug. For most users, the BPR5ES BR6ES family in the listed gap works well, but consult your manual for exact guidance tied to your model year and emissions kit.
How to replace the spark plug
Follow these steps to replace the spark plug on a GX160 and ensure proper seating and gap.
- Disconnect the spark plug boot from the spark plug to prevent any accidental spark or starting the engine.
- Clean the area around the spark plug to prevent dirt from entering the combustion chamber when the plug is removed.
- Use a 13/16-inch (20 mm) spark plug wrench to remove the old plug by turning counterclockwise.
- Check the new plug gap with a feeler gauge and set it to 0.028–0.031 inches (0.7–0.8 mm) if necessary.
- Thread the new plug in by hand to avoid cross-threading, then snug it securely and finish with a light final tighten to the recommended torque (typically around 9–12 ft-lb / 12–16 N·m, depending on manual guidance).
- Reconnect the spark plug boot, start the engine, and verify smooth operation without misfires.
Concluding note: Proper torque and correct gap are essential for reliable starting and performance. If the engine hesitates or misfires after replacement, recheck the gap and ensure the boot is fully seated.
Additional considerations and maintenance tips
Other factors can affect spark plug choice and maintenance for a GX160. Environmental conditions, fuel quality, and maintenance interval all influence plug life and performance. If you’re using ethanol-blended fuels, consider inspecting and replacing plugs more frequently, as deposits can form more quickly. Always carry a spare plug or two with you when operating in remote settings.
Summary
For most Honda GX160 engines, use an NGK spark plug with a 14 mm thread, typically the BPR5ES, and set the gap to 0.028–0.031 inches. An alternative commonly used is BR6ES. Verify the exact specification for your model in the owner's manual or on the engine label, and follow proper replacement and torque guidelines to ensure reliable starts and optimal performance.