NGK CR6HS Spark Plug – Fits Suzuki, Mercury & Yamaha Outboards (Replaces 7023)
NGK CR6HS Spark Plug – Fits Suzuki, Mercury & Yamaha Outboards (Replaces 7023) is backordered and will ship as soon as it is back in stock.
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Worry-free returns
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Delivery and Shipping
Delivery and Shipping
Free standard shipping on all orders under 1 KG
NGK CR6HS Spark Plug – Fits Suzuki, Mercury & Yamaha Outboards ...
Product Details
This standard NGK CR6HS Spark Plug is designed for reliable ignition in a range of small outboard engines and personal watercraft. It is a direct fit for various Suzuki 50–80cc outboard engines, 1995–1998 Mercury/Mariner 9.9HP 4-Stroke outboards, and 1985–2004 Yamaha F9.9 & T9.9 4-Stroke models.
This part serves as a direct replacement for NGK stock numbers 7023 and 4042.
- Engineered for standard gasoline applications.
- Features a threaded stud terminal for secure connection.
- Durable construction with an aluminum silicate ceramic insulator.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number | Notes |
|---|---|---|
| NGK | CR6HS | Standard Part Number |
| NGK | 7023 | Stock Number for CR6HS |
| NGK | 4042 | Alternate Stock Number |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
For Suzuki Owners: This plug fits various AE, AH, AP, and FR series models from the 1970s through the 1990s.
For Mercury/Mariner Owners: Primarily for the 9.9HP (232cc) 4-Stroke engine from 1995–1998.
For Yamaha Owners: Fits F9.9 and T9.9 4-stroke models across a wide range of years, including specific serial number prefixes.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Suzuki | AE | 50 | 1990–1996 | Style model | ||
| Suzuki | AH | 50 | 1992–1995 | Address model | ||
| Suzuki | AP | 50 | 1976–1999 | |||
| Suzuki | FR | 80 | 1984–1987 | |||
| Mercury | 9.9HP 232cc | 9.9 | 4-Stroke | 1995–1998 | ||
| Yamaha | F9.9 | 9.9 | 4-Stroke | 1985–2003 | All models | |
| Yamaha | F9.9 (6G8) | 9.9 | 4-Stroke | 2004 | Serial Number Starting with 6G8 | |
| Yamaha | T9.9 | 9.9 | 4-Stroke | 1985–1991 | ||
| Yamaha | T9.9 (6G8) | 9.9 | 4-Stroke | 1992–2004 | Serial Numbers Starting with 6G8 | |
| Yamaha | Z50RD | 1986 | Honda model reference |
Technical Specs
- Product Type
- Standard Spark Plug
- Installation
- Threaded
- Fuel Type
- Gasoline
- Connection
- Threaded Terminal
- Housing Material
- Aluminum Silicate Ceramic Insulator with Metal Shell
- Housing Color
- Silver/Metallic
- Overall Dimensions
- 8.0" L x 2.0" W x 1.8" H
- Weight
- 2.24 oz (63.5g)
- Fitting Type
- Threaded
- Thread Size
- 10mm x 1.0mm Pitch
- Thread Reach
- 12.7mm (1/2")
- Heat Range
- 6 (Medium)
- Terminal Type
- Threaded Stud
- Hex Size
- 16mm (5/8")
- Spark Gap
- 0.7mm (0.028")
- Resistor
- Yes (5k Ohms)
- Ground Electrode
- Nickel, Standard Configuration, Single
- Center Electrode
- Nickel, Standard Type, 2.5mm, Non-Projected
- Recommended Torque
- Cast Iron: 18-25.3 lb. ft., Aluminum: 18-21.6 lb. ft.
- Longevity
- Approximately 30,000 miles
What’s in the Box
- 1 x Standard Spark Plug (NGK CR6HS 7023)
Installation Notes
- Ensure the engine is completely cool before starting work.
- Disconnect the battery as a safety precaution.
- Clean the area around the old spark plug to prevent debris from entering the cylinder.
- Carefully remove the old spark plug using an appropriate socket wrench.
- Verify the gap on the new spark plug is set to 0.7mm (0.028") before installation.
- Hand-tighten the new spark plug into the cylinder head to avoid cross-threading.
- Use a torque wrench to tighten the plug to the recommended specification: 18–21.6 lb. ft. for aluminum heads or 18–25.3 lb. ft. for cast iron heads.
- Securely re-attach the spark plug wire/boot.
- Reconnect the battery, start the engine, and check for smooth operation.
Troubleshooting & FAQ
How do I confirm this spark plug fits my specific engine?
While this plug fits many models, always verify compatibility by checking your engine's model and year against the compatibility table on this page. Comparing the technical specifications—especially thread size (10mm), reach (12.7mm), and hex size (16mm)—to your old part is also a reliable method.
What is the correct spark plug gap and should I adjust it?
The pre-set gap for the NGK CR6HS is 0.7mm (0.028"). It's always best practice to verify this gap with a feeler gauge before installation, as it can shift during shipping.
What are the signs of a worn or failing spark plug?
Common symptoms include engine misfires, rough idling, difficulty starting the engine, reduced power, and decreased fuel efficiency. Visual inspection may reveal a fouled, burned, or worn electrode.
How often should this spark plug be replaced?
The estimated service life is approximately 30,000 miles under normal operating conditions. However, for marine engines, it's good practice to inspect them annually and replace as needed based on condition and hours of use.
What does the 'R' in CR6HS signify?
The 'R' indicates that this is a resistor-type spark plug, featuring a 5k Ohm resistor. This helps suppress ignition noise and prevent interference with onboard electronics.
OEM vs. Aftermarket?
This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.
Shipping speed & cost?
We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.
Warranty & returns?
Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.
Safety & Important Info
- Verify images/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.
- This is an aftermarket replacement, not an OEM component.
- Professional installation is recommended for safety and performance.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
- Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
- Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.
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