Honda Lawn Mower Spark Plug Gap Chart

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 ModelEngine ModelSpark PlugGap (inches)Gap (mm)
HRX217VKAGCV200NGK BPR5ES0.028–0.0310.7–0.8
HRX217HYAGCV200NGK BPR5ES0.028–0.0310.7–0.8
HRX217HZAGCV200NGK BPR5ES0.028–0.0310.7–0.8
HRX217VYAGCV200NGK BPR5ES0.028–0.0310.7–0.8
HRX217K6HYAGCV200NGK BPR5ES0.028–0.0310.7–0.8
HRX217K6VKAGCV200NGK BPR5ES0.028–0.0310.7–0.8
HRN216VKAGCV170NGK BPR6ES0.028–0.0310.7–0.8
HRN216PKAGCV170NGK BPR6ES0.028–0.0310.7–0.8
HRN216VLAGCV170NGK BPR6ES0.028–0.0310.7–0.8
HRN216VYAGCV170NGK BPR6ES0.028–0.0310.7–0.8
HRR216VKAGCV160NGK BPR6ES0.028–0.0310.7–0.8
HRR216PKAGCV160NGK BPR6ES0.028–0.0310.7–0.8
HRR216VLAGCV160NGK BPR6ES0.028–0.0310.7–0.8
HRR216VYAGCV160NGK BPR6ES0.028–0.0310.7–0.8
HRS216PKAGCV160NGK BPR6ES0.028–0.0310.7–0.8
HRS216VKAGCV160NGK BPR6ES0.028–0.0310.7–0.8
HRC216HXAGXV160NGK BPR5ES0.028–0.0310.7–0.8
HRC216PDAGXV160NGK BPR5ES0.028–0.0310.7–0.8
HRC216K3HDAGXV160NGK BPR5ES0.028–0.0310.7–0.8
HRC216K3PDAGXV160NGK BPR5ES0.028–0.0310.7–0.8
H1011S (Riding Mower)GXV340NGK BPR5ES0.0300.75
H3011H (Riding Mower)GXV340NGK BPR5ES0.0300.75
H4514H (Riding Mower)GXV390NGK BPR5ES0.0300.75
H5518 (Riding Mower)GX390NGK BPR6ES0.0300.75
HRM215SDAGCV160NGK BPR6ES0.028–0.0310.7–0.8
HRM215HXAGCV160NGK BPR6ES0.028–0.0310.7–0.8
HRT216TDAGCV160NGK BPR6ES0.028–0.0310.7–0.8
HRT216SDAGCV160NGK BPR6ES0.028–0.0310.7–0.8
Harmony II HRT216GCV160NGK BPR6ES0.028–0.0310.7–0.8
Harmony HRS21G150NGK BPMR6Y0.0300.75
Harmony HRB215GCV160NGK BPR6ES0.028–0.0310.7–0.8
Miimo HRM310Brushless MotorN/A (Electric)N/AN/A
Miimo HRM520Brushless MotorN/A (Electric)N/AN/A
Miimo HRM40Brushless MotorN/A (Electric)N/AN/A
HRR216K9VKAAGCV160NGK BPR6ES0.028–0.0310.7–0.8
HRR216K10VKAGCV160NGK BPR6ES0.028–0.0310.7–0.8
HRS216K5PKUAGCV160NGK BPR6ES0.028–0.0310.7–0.8
HRS216K6VKAAGCV160NGK BPR6ES0.028–0.0310.7–0.8
HRX217K5VKAGCV190NGK BPR6ES0.028–0.0310.7–0.8
HRX217K4HYAGCV190NGK BPR6ES0.028–0.0310.7–0.8
HRC216K2HDAGXV160NGK BPR5ES0.028–0.0310.7–0.8
GCV135 Engine ModelsGCV135NGK BPR6ES0.028–0.0310.7–0.8
GCV190 Engine ModelsGCV190NGK BPR6ES0.028–0.0310.7–0.8
GXV120 (Old Models)GXV120NGK BPR6ES0.0300.75
GXV140 (Old Models)GXV140NGK BPR5ES0.0300.75
GXV160 (Old Models)GXV160NGK BPR5ES0.028–0.0310.7–0.8

Related Honda Lawn Mower Comparison Chart(For All Models)

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.

George Bill
George Bill

George Bill is a Mechanical Engineer by Profession and an avid gardener and has been mowing his lawn for over 20 years. He has used a variety of different mowers during this time.
George is an expert at maintaining his mowers and over the years, he has learned many tricks and techniques for getting the best results from his mowers and is always happy to share his knowledge on this site.

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