Independent comparisons. We may earn from shop links. More info

Best lawn mower spark plug for a code you already know

Updated: October 2026

You already know the stamp on the old plug, and you want one listing from this amazon.co.uk set rather than another chart. The best lawn mower spark plug in that narrow sense is the row whose code matches, with a limit you can live with. The highest star line and the lowest price are different plugs, for different engines. There is no single winner. The [spark plug lawnmower comparison](/hub/lawn-and-garden-equipment/spark-plug-lawnmower) holds all twelve listings. Prices are the saved shelf figures, from about £3.54 to about £8.89, not a live scrape. Peter F. did not lab-test the plugs. A qualifying purchase can earn a commission at no extra cost to you.

You already know the stamp on the old plug, and you want one listing from this amazon.co.uk set rather than another chart.

Our top picks

Briggs & Stratton Briggs & Stratton RC12YC pair

Best overall

Briggs & Stratton Briggs & Stratton RC12YC pair
9.6/10about £7.99
View offer
NGK NGK BPMR7A

Best value

NGK NGK BPMR7A
9.4/10about £3.91
View offer
UYUYong UYUYong RJ19LM, 3

Rank 3

UYUYong UYUYong RJ19LM, 3
8.6/10about £4.89
View offer
On this page
  1. 1.There is no best plug until the code matches
  2. 2.Overhead-valve Briggs pair
  3. 3.Short-reach NGK single
  4. 4.Flathead three-pack and the BPR5ES single
  5. 5.What not to treat as a pick

There is no best plug until the code matches

Briggs & Stratton UK does not publish one plug for every small engine. Flathead, overhead valve, Quantum and short-reach two-stroke are different rows, and a plug that screws in can still be wrong. A 4.8 line does not override that. A score here is the amazon.co.uk star figure times 20, minus 8 when the review count is under 100, and it is not a lab test. RC12YC, BPMR7A, RJ19LM and BPR5ES are conditional picks. The cheapest plug is not the best value.

Overhead-valve Briggs pair

The RC12YC pair is the top pick only for an overhead-valve Briggs engine whose parts list calls for that code. The score is 96. UK reviews include a Masport that fired on the first pull and a Mountfield that fitted. The warranty cell says 12 months. Skip it for a flathead, for a Quantum row that wants 0.020 in, or for overhead cam. One review bought the pair in error for an overhead-cam engine. Another says the terminal would not seat in a new genuine Briggs coil boot that had taken a Champion RC12YC. The title says two plugs and the Number of Items cell says 1. Count what arrives. A car-plug rank does not change the code.
Briggs & Stratton Briggs & Stratton RC12YC pair

Testsieger

Briggs & Stratton Briggs & Stratton RC12YC pair
9.6/10about £7.99
View offer

Short-reach NGK single

The BPMR7A single is the value pick, score 94, and it is not the lowest price. Use it when the old plug or the manual already says BPMR7A. Husqvarna UK lists that code on brushcutters and chainsaws. A lawn-mower rank is not proof it belongs in a four-stroke mower, so skip it for RJ19LM or RC12YC. The NGK page states 9.5 mm reach and a 0.7 mm gap. The amazon.co.uk gap cell prints 9.5 mm and does not say which dimension that is. One UK review said the resistor was a poor swap for a non-resistor CJ8. An Adefol cross at about £4.74 has a thread cell that says M10, so the named NGK single is the cleaner row.

Flathead three-pack and the BPR5ES single

If the old plug reads RJ19LM, the UYUYong three-pack is about £4.89, 4.3 from 153 reviews. The bullets name Classic, Sprint, Quattro and Quantum. UK reviews include a mower that ran, a nut that will not take a 13/16 socket, and a Macallister that stopped because the plugs overheated. Quantum still needs the code date. It is not an overhead-valve plug. The BPR5ES single scores 92 and does not take the value badge. Core and top cells say iridium and the type name does not. One delivery arrived loose in an envelope, which can knock the gap. One review says a Mountfield ST100 needs BPR6ES.

What not to treat as a pick

Two listings have no customer-reviews line, so they score 0. The Talinco two-pack at about £4.99 mixes an L7T included line with Classic, Sprint, Quattro and Quantum. The OmniCraft plug at about £5.39 is marked BPMR7A for small two-stroke engines, with no thread or gap printed. The Hawpasy F7RTC pair at about £5.79 is 4.5 from 11 reviews, and the only UK review text is Super. If your code is not in this set, use the buying guide.

Common questions

What is the best lawn mower spark plug on amazon.co.uk?
In this saved set, the highest score is the Briggs & Stratton RC12YC pair at about £7.99, 4.8 from 2,482 reviews. That is a top pick only when your parts list says RC12YC. It is the wrong plug for a flathead RJ19LM engine and for a Quantum row that wants 0.020 in. Stars do not measure fit.
Is the cheapest plug the best value?
No. The cheapest listing here is the BPR5ES at about £3.54. The best value in this set is the BPMR7A at about £3.91, with 5,929 reviews, because the price is still low and the sample is much larger, for engines that already use that code. A heat-range complaint on the cheaper plug, and iridium cells that disagree with the type name, are why the lowest price does not take that place.
Which plug if I have a two-stroke strimmer, not a mower?
Look for BPMR7A or the L7T cross your old plug already shows. The NGK BPMR7A at about £3.91 is the value row for that code. The VZU six-pack at about £8.89 makes sense only if several tools share it. Do not fit an RC12YC or RJ19LM plug into a strimmer because both packets mention garden equipment.
Should I buy the six-pack?
Only if several tools already share the code. The VZU L7T six-pack is about £8.89 from 18 reviews, and the warranty cell says no. One walk-behind does not use six plugs.
Can I trust a listing with no reviews?
You can read the title, and you cannot score it. Talinco at about £4.99 and OmniCraft at about £5.39 have no customer-reviews line, so both score 0. Talinco does not settle whether you are buying L7T or a flathead plug. Pay only if you can read the marking on arrival.
Is a Briggs plug worth more than an NGK?
Only when the engine asks for the Briggs code. The RC12YC pair is about £7.99. The NGK BPMR7A is about £3.91 and has more reviews because it is a saw and strimmer plug, not a cheaper copy of the same part.

Related pages

RJ19LM vs RC12YC

How to change a lawn mower spark plug

Spark plug lawnmower

Which lawn mower spark plug matches the engine code

Lawn mower won't start spark plug checks before you buy

Sources

Buying notes from the sources below, checked for this page on 22 October 2026. Prices, stars and review counts are from the amazon.co.uk captures of that date. Two listings had no customer-reviews line.

  1. Briggs & Stratton UK: identifying the correct spark plug and gap (retrieved 22 October 2026)
  2. Briggs & Stratton UK: servicing the spark plug (retrieved 22 October 2026)
  3. Briggs & Stratton UK: engine problem solving (retrieved 22 October 2026)
  4. NGK: BPMR7A nickel spark plug (retrieved 22 October 2026)
  5. Husqvarna UK: spark plug spare (retrieved 22 October 2026)
  6. Husqvarna UK: how to check a spark plug gap (retrieved 22 October 2026)
  7. HSE: staying safe with petrol (retrieved 22 October 2026)
  8. Consumer Rights Act 2015, section 9 (retrieved 22 October 2026)