NGK Replacement Spark Plugs CMR7H 6-Pack — 10mm Thread, 12.7mm Reach for Small Engines

NGK CMR7H-6PK is a six-pack of genuine OEM replacement spark plugs designed to restore reliable ignition performance in compatible small engines.

These NGK spark plugs come new and bulk packed, offering the exact dimensions and seat style required for many handheld and compact equipment engines. With a 10 mm thread diameter, 12.7 mm (1/2 inch) reach, 5/8 inch hex, and a solid tip configuration on a gasket seat, they match factory specifications for numerous models and replace comparable parts from other manufacturers.

What engines and brands are these plugs compatible with?

NGK CMR7H-6PK fits a range of small engine applications; compatibility depends on thread, reach, and seat type. They are known to replace certain Champion, Homelite/Jacobsen, NGK part numbers and are listed for some Redmax equipment.

• Replaces Champion RZ7C and Homelite/Jacobsen 870217001, 870301002.
• Equivalent to NGK 3066 and Torch A8RTC in many installations.
• Intended for engines requiring 10 mm threads and a 12.7 mm reach with gasket seats.
• Always verify your equipment’s manual or plug cross-reference before installation.

How do the physical specs affect fit and installation?

Thread diameter, reach, hex size and seat type determine whether a spark plug will fit properly and seal the combustion chamber. Using the correct 10 mm thread and 12.7 mm reach prevents contact with the piston and ensures proper electrode positioning for reliable ignition.

• Thread diameter: 10 mm — matches many small engine spark plug ports.
• Reach: 12.7 mm — ensures correct electrode protrusion into the combustion chamber.
• Hex size: 5/8 in — standard wrench/socket size for installation and removal.
• Seat type: gasket — requires a mating gasket surface for a proper seal.

What performance and durability should I expect from these plugs?

These are standard, solid-tip spark plugs intended for routine ignition duty in small engines. They provide consistent spark delivery when installed and gapped correctly, and their OEM specification ensures predictable service life under normal operating conditions.

• Solid tip design for straightforward, dependable sparking.
• Genuine NGK manufacturing for consistent quality control.
• Sold in a six-pack to replace multiple cylinders or keep spares on hand.
• Bulk packed as new parts for value and convenience.

How do I choose and install the right NGK CMR7H plug?

Select plugs by matching thread size, reach, seat type, and heat range to your engine’s specification. Installation requires the correct socket, torque to manufacturer recommendations, and verification of the electrode gap if your engine manual specifies a setting.

• Confirm compatibility via your equipment manual or part cross-reference list.
• Use a 5/8-inch spark plug socket and torque wrench for correct tightening.
• Set or confirm the gap per the engine manufacturer’s recommendation before installing.
• Replace all plugs on multi-cylinder engines at the same interval for uniform performance.

Who this is for: NGK CMR7H-6PK is aimed at owners and technicians of small engine equipment—lawn and garden tools, handheld power tools, and compact machinery—that require a 10 mm thread, 12.7 mm reach, and gasket-seat spark plug. It suits DIYers, pro landscapers, and maintenance shops needing a six-pack of OEM-quality replacements to keep equipment running smoothly or to stock up for routine tune-ups. Always cross-check part numbers and engine specs before purchase to ensure proper fitment.