The ALM Manufacturing RN9YC Spark Plug is a replacement ignition spark plug suitable for most compatible Honda and MacAllister petrol lawnmowers, as well as many other small petrol engines requiring the corresponding spark plug specification.

Designed for routine engine servicing and replacing worn, fouled or damaged spark plugs, the ALM RN9YC provides a practical replacement option for maintaining the ignition system of compatible garden machinery.

A spark plug is an essential component of a petrol engine. It produces the electrical spark that ignites the fuel-air mixture inside the combustion chamber, allowing the engine to operate.

Over time, spark plugs can become worn, contaminated or damaged, potentially contributing to difficult starting, uneven running or engine misfiring.

The ALM RN9YC compares to several well-known spark plug references, including Champion N9YC and RN9YC, NGK BP6ES and BPR6ES, Bosch WR7DC and Torch F6TC.

Important identification note: Although the ALM product part number is RN9YC, the spark plug itself is printed with ALM 9. This is the expected marking for this replacement part.

Whether you're servicing a Honda petrol lawnmower, maintaining a MacAllister mower or replacing a spark plug in another compatible small engine, the ALM RN9YC offers a convenient ignition maintenance solution.

Key Benefits

• Genuine ALM Manufacturing replacement product

• Part number RN9YC

• Spark plug marked ALM 9

• Suitable for most compatible Honda petrol lawnmowers

• Suitable for most compatible MacAllister petrol lawnmowers

• Suitable for many other small petrol engines requiring this specification

• Useful for replacing worn or fouled spark plugs

• Suitable for routine lawnmower servicing

• Compares to Bosch WR7DC

• Compares to Champion N9YC and RN9YC

• Compares to NGK BP6ES and BPR6ES

• Compares to Denso LR15YC

• Compares to Oregon OLR15YC

• Compares to Rocwood F6RTC

• Compares to Torch F6TC

• Practical for petrol garden machinery maintenance

Important: RN9YC Is Marked ALM 9

The ALM RN9YC Spark Plug is printed with the marking:

ALM 9

This is an important detail when checking the replacement spark plug against its packaging or product description.

The ALM 9 marking corresponds to the ALM RN9YC product.

Do not assume that the marking indicates a different part.

Honda Lawnmower Replacement Spark Plug

The ALM RN9YC is suitable for most Honda petrol lawnmowers requiring the corresponding spark plug specification.

Honda lawnmower engines are used in a wide range of garden machinery, and selecting the correct spark plug is important for proper ignition system operation.

The ALM RN9YC provides a replacement option where the engine manufacturer's specified plug matches the appropriate reference.

Important: Not every Honda lawnmower uses the same spark plug. Always check the engine model and recommended spark plug specification before purchasing.

MacAllister Lawnmower Spark Plug

The ALM RN9YC is also suitable for most compatible MacAllister petrol lawnmowers.

It is a practical replacement part for routine servicing or when the existing spark plug has become worn, fouled or damaged.

Check the original spark plug reference or the engine manufacturer's service information to confirm suitability.

Replacement Spark Plug for Small Petrol Engines

In addition to compatible Honda and MacAllister lawnmowers, the ALM RN9YC is suitable for many other small petrol engines requiring this spark plug specification.

Compatibility depends on the engine's requirements, including the correct thread dimensions, reach, heat range and electrode gap.

Always use the specification recommended by the engine manufacturer.

Spark Plug Cross-Reference Numbers

The ALM RN9YC compares to the following spark plug part numbers.

Bosch

• WR7DC

Champion

• N9YC

• RN9YC

Denso

• LR15YC

NGK

• BP6ES

• BPR6ES

Oregon

• OLR15YC

Rocwood

• F6RTC

Torch

• F6TC

These comparison references can help identify a suitable replacement when checking an existing spark plug or consulting an engine parts list.

Compatibility Note: Cross-reference numbers are provided as identification guidance. Some spark plugs may differ in resistance characteristics or other technical details. Always confirm the correct specification for your particular engine before fitting.

Why a Good Spark Plug Matters

A correctly specified and functioning spark plug is important for petrol engine operation.

The spark plug creates the ignition spark required to start and run the engine.

A worn, fouled or damaged spark plug may contribute to:

• Difficult engine starting

• Intermittent ignition

• Uneven engine running

• Engine misfiring

• Poor idling

• Reduced running performance

These symptoms may also have other mechanical or fuel-system causes, so spark plug replacement is not guaranteed to resolve every engine problem.

When to Replace Your Lawnmower Spark Plug

A spark plug should be inspected as part of routine petrol lawnmower servicing.

Replacement may be necessary when the plug shows:

• Worn electrodes

• Heavy carbon deposits

• Oil contamination

• Cracked ceramic insulation

• Corrosion

• Physical damage

• Excessive wear or deterioration

Follow the engine manufacturer's recommended spark plug inspection and replacement intervals.

How to Fit

1. Switch off the lawnmower and allow the engine to cool completely.

2. Disconnect the spark plug cap.

3. Clean away dirt and debris from around the existing spark plug.

4. Remove the old plug using a suitable spark plug socket.

5. Confirm that the ALM RN9YC (marked ALM 9) is correct for your engine.

6. Check the electrode gap against the engine manufacturer's specification.

7. Carefully thread the replacement spark plug into the cylinder head by hand to avoid cross-threading.

8. Tighten the plug to the manufacturer's specified torque.

9. Reconnect the spark plug cap securely.

10. Ensure the machine is correctly assembled before starting the engine.

Important: Never overtighten a spark plug or force an incorrectly sized plug into the cylinder head. Follow the engine manufacturer's fitting instructions.

Compatible Machinery

The ALM RN9YC is suitable for:

• Most compatible Honda petrol lawnmowers

• Most compatible MacAllister petrol lawnmowers

• Other small petrol engines requiring the corresponding spark plug specification

Note: Compatibility must be confirmed against the engine manufacturer's requirements. No individual mower model numbers are specified for this product.

Complete Part Number Cross-References

• ALM: RN9YC (marked ALM 9)

• Bosch: WR7DC

• Champion: N9YC, RN9YC

• Denso: LR15YC

• NGK: BP6ES, BPR6ES

• Oregon: OLR15YC

• Rocwood: F6RTC

• Torch: F6TC

Ideal For

• Honda petrol lawnmower servicing

• MacAllister petrol lawnmower maintenance

• Replacing worn spark plugs

• Replacing fouled or damaged spark plugs

• Petrol engine ignition maintenance

• Routine lawnmower servicing

• Compatible small petrol engine repairs

• Garden machinery maintenance

• Identifying a replacement for Champion RN9YC

• Finding an alternative to NGK BPR6ES where specified

• Replacing Bosch WR7DC where compatible

Product Information

Brand: ALM Manufacturing
Product: Spark Plug
Part Number: RN9YC
Marking on Spark Plug: ALM 9
Type: Replacement petrol engine ignition spark plug
Compatible Brands: Honda, MacAllister and other compatible small petrol engines
Primary Machinery: Petrol lawnmowers
Bosch Comparison: WR7DC
Champion Comparisons: N9YC, RN9YC
Denso Comparison: LR15YC
NGK Comparisons: BP6ES, BPR6ES
Oregon Comparison: OLR15YC
Rocwood Comparison: F6RTC
Torch Comparison: F6TC
Primary Use: Replacing worn, fouled or damaged spark plugs in compatible petrol lawnmowers and small engines.

WEEE Recycling Producer Registration Number:12889

How do I return my old product to be recycled?

You can return your old product to MyDIY. Waste Electrical and Electronic Equipment (WEEE) is taken back free of charge on a one-for-one, like-for-like basis. Waste batteries including rechargeable batteries are taken back free of charge. You are not obliged to make any purchase when returning old batteries. Each local authority must also accept household WEEE and small batteries free of charge at its recycling facilities. All WEEE and waste batteries must be recycled and should not be placed in any of your household wheelie bins. Make sure you always recycle all your old electrical goods and batteries.

What products can I recycle for free?

You can return anything that is electricaly powered or battery powered. Even your old bicycle lamps can be recycled!.

Do you take back used batteries?

Yes we do. The batteries that we accept are AA, AAA, C or D, powertool batterys and also the flat batteries that are found in watches and toys. Unfortunately we do not accept back any Industrial or car batteries.

Do I need to have made a purchase at MyDIY.ie?

No you don't. You can recycle any of the above items at our store in Inchicore Dublin 8, even if you have not made a purchase with us.

Will you collect my old product?

Yes, but we must be notafied within 14 days of purchase date. You can still arrange to have your old appliance recycled free of charge. Simply bring it back to our Inchicore store and we will ensure that it is disposed of in an environmentally friendly manner.

How much will it cost?

There is no charge to return products to any of our warehouses.

Why should I recycle with MyDIY?

We will ensure that your old product is disposed of correctly to reduce the potentially harmful effects caused on the environment and to conserve natural resources. Further information can be found on weeeireland.ie.

EMC (Environmental Management Cost) Included in the purchase price. 

Gas discharge lamps, LFLs and CFLs €0.15

LED lamps and luminaires €0.05

Large appliances €5.00

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Customer Service & Returns

• Great service as usual. Thanks

  5/5

  Written by: Mr Hernon

  Date: 19/02/2019