Honda Lawn Mower Spark Plug Gap Chart(For All Models)

One often-overlooked detail can make a world of difference, the spark plug gap. This small specification has a big impact on ignition timing, engine start-up, fuel combustion, and overall mower performance.

In this guide, we’ll walk through everything you need to know about Honda mower spark plugs, followed by a detailed Honda lawn mower spark plug gap chart for all major models.

Honda Lawn Mower Spark Plug Gap Chart

Mower Model	Engine Model	Spark Plug	Gap (inches)	Gap (mm)
HRX217VKA	GCV200	NGK BPR5ES	0.028–0.031	0.7–0.8
HRX217HYA	GCV200	NGK BPR5ES	0.028–0.031	0.7–0.8
HRX217HZA	GCV200	NGK BPR5ES	0.028–0.031	0.7–0.8
HRX217VYA	GCV200	NGK BPR5ES	0.028–0.031	0.7–0.8
HRX217K6HYA	GCV200	NGK BPR5ES	0.028–0.031	0.7–0.8
HRX217K6VKA	GCV200	NGK BPR5ES	0.028–0.031	0.7–0.8
HRN216VKA	GCV170	NGK BPR6ES	0.028–0.031	0.7–0.8
HRN216PKA	GCV170	NGK BPR6ES	0.028–0.031	0.7–0.8
HRN216VLA	GCV170	NGK BPR6ES	0.028–0.031	0.7–0.8
HRN216VYA	GCV170	NGK BPR6ES	0.028–0.031	0.7–0.8
HRR216VKA	GCV160	NGK BPR6ES	0.028–0.031	0.7–0.8
HRR216PKA	GCV160	NGK BPR6ES	0.028–0.031	0.7–0.8
HRR216VLA	GCV160	NGK BPR6ES	0.028–0.031	0.7–0.8
HRR216VYA	GCV160	NGK BPR6ES	0.028–0.031	0.7–0.8
HRS216PKA	GCV160	NGK BPR6ES	0.028–0.031	0.7–0.8
HRS216VKA	GCV160	NGK BPR6ES	0.028–0.031	0.7–0.8
HRC216HXA	GXV160	NGK BPR5ES	0.028–0.031	0.7–0.8
HRC216PDA	GXV160	NGK BPR5ES	0.028–0.031	0.7–0.8
HRC216K3HDA	GXV160	NGK BPR5ES	0.028–0.031	0.7–0.8
HRC216K3PDA	GXV160	NGK BPR5ES	0.028–0.031	0.7–0.8
H1011S (Riding Mower)	GXV340	NGK BPR5ES	0.030	0.75
H3011H (Riding Mower)	GXV340	NGK BPR5ES	0.030	0.75
H4514H (Riding Mower)	GXV390	NGK BPR5ES	0.030	0.75
H5518 (Riding Mower)	GX390	NGK BPR6ES	0.030	0.75
HRM215SDA	GCV160	NGK BPR6ES	0.028–0.031	0.7–0.8
HRM215HXA	GCV160	NGK BPR6ES	0.028–0.031	0.7–0.8
HRT216TDA	GCV160	NGK BPR6ES	0.028–0.031	0.7–0.8
HRT216SDA	GCV160	NGK BPR6ES	0.028–0.031	0.7–0.8
Harmony II HRT216	GCV160	NGK BPR6ES	0.028–0.031	0.7–0.8
Harmony HRS21	G150	NGK BPMR6Y	0.030	0.75
Harmony HRB215	GCV160	NGK BPR6ES	0.028–0.031	0.7–0.8
Miimo HRM310	Brushless Motor	N/A (Electric)	N/A	N/A
Miimo HRM520	Brushless Motor	N/A (Electric)	N/A	N/A
Miimo HRM40	Brushless Motor	N/A (Electric)	N/A	N/A
HRR216K9VKAA	GCV160	NGK BPR6ES	0.028–0.031	0.7–0.8
HRR216K10VKA	GCV160	NGK BPR6ES	0.028–0.031	0.7–0.8
HRS216K5PKUA	GCV160	NGK BPR6ES	0.028–0.031	0.7–0.8
HRS216K6VKAA	GCV160	NGK BPR6ES	0.028–0.031	0.7–0.8
HRX217K5VKA	GCV190	NGK BPR6ES	0.028–0.031	0.7–0.8
HRX217K4HYA	GCV190	NGK BPR6ES	0.028–0.031	0.7–0.8
HRC216K2HDA	GXV160	NGK BPR5ES	0.028–0.031	0.7–0.8
GCV135 Engine Models	GCV135	NGK BPR6ES	0.028–0.031	0.7–0.8
GCV190 Engine Models	GCV190	NGK BPR6ES	0.028–0.031	0.7–0.8
GXV120 (Old Models)	GXV120	NGK BPR6ES	0.030	0.75
GXV140 (Old Models)	GXV140	NGK BPR5ES	0.030	0.75
GXV160 (Old Models)	GXV160	NGK BPR5ES	0.028–0.031	0.7–0.8

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How to Check and Adjust Spark Plug Gap

To inspect and set the spark plug gap correctly, follow these simple steps:

Tools You’ll Need:

• Gap gauge or feeler gauge
• Flathead screwdriver (for adjusting)
• Clean cloth

Steps:

1. Remove the spark plug using a wrench.
2. Inspect the plug for wear, deposits, or damage.
3. Insert the gauge between the electrodes to check the gap.
4. If the gap is incorrect, gently bend the ground electrode (not the center electrode) to open or close the gap.
5. Recheck the gap and reinstall the spark plug.

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Signs of Incorrect Spark Plug Gap

If the spark plug gap isn’t set properly, your mower may exhibit the following symptoms:

• Hard starting
• Poor fuel economy
• Rough idling
• Misfiring or backfiring
• Reduced engine power
• Unusual engine sounds

Maintaining the correct gap not only restores your mower’s performance but also prevents costly engine repairs.

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When to Replace the Spark Plug

Honda recommends replacing the spark plug:

• Every 100 hours of use or annually, whichever comes first.
• If it shows signs of fouling, corrosion, or electrode erosion.

Using OEM spark plugs (like NGK or Denso) is always a safer bet than cheap aftermarket versions, especially if you want consistent performance.

FAQs

What is the spark plug gap for a Honda lawn mower?

Most Honda lawn mowers use a standard spark plug gap of 0.028–0.031 inches (or 0.7–0.8 mm). This applies to common engines like the GCV160, GCV170, GCV190, and GCV200.

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How much gap for lawn mower spark plug?

The correct spark plug gap for most 4-stroke gas-powered lawn mowers, including Honda, is between 0.028 and 0.031 inches. Always check your owner’s manual for exact specs.

What is the spark plug gap for a Honda GCV160?

The Honda GCV160 engine uses an NGK BPR6ES spark plug with a gap of 0.028–0.031 inches (0.7–0.8 mm).

What is the spark plug gap on a Honda GCV190?

The Honda GCV190 engine also uses the NGK BPR6ES spark plug with a recommended gap of 0.028–0.031 inches (0.7–0.8 mm).

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What is the spark plug gap on a Honda FG110?

The Honda FG110 mini-tiller uses a NGK CMR5H spark plug with a slightly smaller gap:

0.024–0.028 inches (0.6–0.7 mm).

What does too much spark plug gap do?

If the spark plug gap is too wide, the spark may be weak or fail to jump the electrodes consistently. This can cause:

• Hard starting
• Engine misfires
• Poor fuel economy
• Rough idling
• Reduced engine power

What is the spark plug gap on a 2015 Honda lawn mower?

Most 2015 Honda mowers (like HRR or HRS models with GCV160 engines) still follow the same spec:

0.028–0.031 inches (0.7–0.8 mm) using an NGK BPR6ES plug.