Explore 7 Best Spark Plugs For Mercury 2 Stroke Outboard In 2023

Are you searching for the best spark plugs for a mercury 2-stroke outboard but had no luck so far? If yes, then you have reached the right place.

Spark plugs are integral to your engine. They are the electrical devices responsible for igniting your combustion engine with a spark and helping it start.

Many automobile owners are not even aware of this part, and for some, these hold no importance. However, every car owner should know that spark plugs are one of the most crucial components of gasoline-powered automobiles.

A dysfunctional spark plug can create a significant issue with your ride. Sometimes, more than you can anticipate. Most of the time, if you find your ride giving you a hard time while starting, it may be the faulty spark plugs.

So, you need to replace them but only with the best quality. Thus, we bring you this buying guide of the best spark plugs for a 2-stroke outboard to ensure your engine is just as smooth as a brand-new one.

What Are the Top Reasons That Causes The Spark Plugs To Wear Out?

As stated above, spark plugs are a crucial component of a gasoline engine. They provide the much-needed spark to ignite the engine to life.

Spark plugs are connected to the ignition coil, which generates the voltage that sparks the air or fuel and starts the combustion process powering the engine.

To ensure the smooth operation of your engine, the spark plugs must be in good shape. It means no wear & tear and no buildup.

However most vehicle owners cannot avoid the damage to their spark plugs mainly because they do not know what causes their outboard motor spark plugs to degrade over time.

You can only avoid a problem if you know what causes it. To help you take better care of your gasoline engine, we have listed some of the primary reasons your spark plugs are not working correctly.

A. Oil In Combustion Chamber

One of the biggest reasons spark plugs degrade is the engine oil leaking into the combustion chamber. There are many times that we see cars & motorbikes losing oil but not leaking or smoking. It is because the oil is entering the combustion chamber.

This oil leakage leads to the spark plugs getting all oily, further leading to the settlement of surrounding dirt and premature failure. So, you must look at your spark plugs if you find your ride burning too much engine oil.

B. Carbon Buildup

As the engine burns the gas, there is always carbon residue present. If not cleaned regularly, the carbon buildup increases on the spark plugs hindering their working. You will find issues like hard starts, engine misfires, reduced acceleration, and check engine light coming on.

Carbon buildup makes the spark plugs hard and decreases their lifespan. Dirty air filters, too-rich fuel & air mixture, and continuous driving at low speeds are prime reasons for carbon buildup in the engine.

C. Overheating

If your spark plugs are overheating repeatedly, the excessive heat can lead to premature failure of the tip. Pre-ignition and a malfunctioning cooling system are among the primary reasons for overheating.

Overheating generally leads to the faster wearing of the spark plugs’ electrodes, thus damaging them. So, keep a check on your engine for overheating. If it is a frequent occurrence, have a professional look at it.

D. Unsuitable Spark Plug Gap

For the spark plugs to work correctly, the gap between the center and side electrodes of the devices needs to be precise. Your engine will perform optimally only if the spark plugs are aligned correctly.

If the gap is not optimum, extra stress is placed on the plugs’ tips, resulting in premature wearing & eroding.

7 Best Spark Plugs For Mercury 2 Stroke Outboard In 2023

Now that you know what can cause your spark plugs to fail and the ideal ways to buy a new one, it is time to move forward. Finding a suitable replacement for your automobile parts is tricky. Many options are available in both the online & offline markets, making the selection even more difficult.

You can still feel relieved when looking for more extensive parts like tires, car seat covers, & more. But it gets overwhelming when looking for smaller parts like car brake pads, spark plugs, & other similar ones.

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Most buyers either end up with the wrong product or a poor-quality one. To ensure no such thing happens to you, we have handpicked the 7 best spark plugs for 2-stroke outboard in 2023.

We have reviewed each product thoroughly so you can explore and check which one suits your ride the best. Let us start and check out some good purchases for your outboard engine.

1. E3 Spark Plugs’ Corrosion Resistant, Universal Fit E3.36 Powersports Spark Plug Offering Faster Starts

Best spark plugs for mercury 2 stroke outboard
  • Brand- E3 Spark Plugs
  • Core Material- Copper
  • Top Material Type- Alloy Steel
  • Gap Size- 0.04 Inches
  • Item Weight- ‎1.92 ounces
  • Product Dimensions- ‎6.5 x 4.5 x 0.8 inches
  • Vehicle Service Type- Motorcycle, Fit- Universal Fit
  • The open design ensures more complete combustion
  • Offer more power
  • Helps reduce emissions, Offers faster starts
  • Comes with a five-year warranty
  • Improve fuel economy
  • Nickel plated terminal end offers protection from corrosion
  • Better heat transfer, Helps to reduce harmful emissions

This is a 12mm, 0.750-inch spark plug made of alloy steel. It comes with a gasket seat designed for power application and is an ideal choice for motorcycles.

So, this product will not disappoint you if you are exclusively looking for Yamaha 2-stroke outboard spark plugs or any other prominent bike model.

Also, it can be used in other motor vehicles like cars, snowmobiles, trucks, chainsaws, lawnmowers, and more. It features a patented Diamondfire Ground Electrode secured to the shell with two legs.

The electrode offers faster starts, superior power, better fuel economy, and lower emissions in the long run. Also, the two securing legs help facilitate better heat transfer and withstand the intense vibration coming from the engine.

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In addition, this product comes with a five-year warranty, which showcases the manufacturer’s belief in the product and its high-end quality. Overall, we like its effortless design, which ensures long life and saves your time & money.


  • Good construction
  • Offer easy & faster starts in any conditions
  • Can withstand hot & cold temperatures
  • Improve fuel efficiency
  • Helps to reduce harmful emissions
  • Comes with a five-year warranty
  • Nickel plated terminal end offers protection from corrosion
  • Compatible with several applications like cars, trucks, watercraft, & more


  • The installation can be tricky for the first timers
  • The difference might not be noticeable instantly
  • Available in a single piece

2. Autolite Nickel-plated Iridium XP Vehicle Replacement Spark Plugs To Improve Ignitability and fuel Economy

best spark plugs for 2 stroke outboard
  • Brand- Autolite
  • Core Material- Iridium
  • Top Material Type- Nickel
  • Gap Size- 0.35 to 0.45 inches
  • Item Weight- ‎‎1.92 ounces
  • Product Dimensions- ‎1 x 1 x 3.38 inches
  • Vehicle Service Type- Universal
  • Fit- Universal Fit
  • It features an iridium-enhanced fine wire center electrode
  • Nickel nickel-plated shell offers resistance to corrosion
  • High-alumina ceramic insulation offers boosted strength
  • It comes with platinum sidewire technology
  • Improve ignitability
  • Enhance fuel economy (less fuel consumption)
  • Comes with a limited lifetime warranty

If you wish to purchase a good quantity of spark plugs at once and at a reasonable price, this Autolite pack of four is an excellent choice. The product comes in a pack of four with well-detailed step-by-step DIS and COP instructions.

The electrode of the spark plugs is made of iridium and is coated with a layer of nickel to keep the corrosion at bay. The top end of the plugs comprises a high-aluminum ceramic insulator, which provides a much-needed increase in strength.

These plugs are made to offer good durability. They are engineered with more focused ignition meaning less fuel consumption and better performance.

Also, the manufacturer claims the plugs can last up to 100,000 miles, depending on your engine type. Such a bold claim makes it one of the most durable spark plugs on the market.

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Furthermore, you can use this product in cars, motorcycles, ATVs, snowmobiles, watercraft, trucks, Powersports, chainsaws & other similar pieces of machinery.

This brand has been in the American automotive market for several decades. With such credibility & reliability, you can trust this for your OE replacement spark plug requirements.


  • Offer quick ignition
  • Compatible with most engine-driven pieces of machinery
  • Optimize fuel economy
  • Highly durable & long-lasting
  • Comes with corrosion corrosion-resistant nickel-plated shell
  • The high-alumina ceramic insulator increases the overall strength
  • It comes with well-detailed DIS & COP instructions
  • Comes with a limited lifetime warranty


  • Not suitable for all model-year vehicles
  • You may need to gap the plugs (as per your vehicle’s specification) after the purchase

3. Bosch No Gapping/Adjustment Automotive spark plug for efficient combustion & prolong usage

best spark plugs for mercury 4-stroke outboard
  • Brand- Bosch Automotive
  • Core Material- Platinum
  • Top Material Type- Nickel
  • Item Weight- ‎‎‎0.353 ounces
  • Vehicle Service Type- Car
  • Easy installation
  • Boost engine performance
  • Delivers the longest & most powerful spark
  • Offers the best access to air/fuel mixture for efficient combustion
  • No gapping or adjustment is required
  • Well reputed brand
  • The yttrium-enhanced ground electrodes reduce wear & boost service life

Regarding automobile accessories, BOSCH is a well-reputed and highly acclaimed brand name. The company is hailed for offering only the best to its customers and stands true to this product. This Bosch spark plug features four yttrium-enhanced ground electrodes, which offer vital ignition and robust engine performance.

The plug comprises four electrodes that offer optimum access to air & fuel mixture and give you the most efficient combustion.

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The heat-fused center electrode with pure platinum provides high-end engine performance, smoother acceleration, and good fuel economy. Also, the electrodes work well in reducing gaps and oxidation for better performance and extended usage.

The installation of this Bosch spark plug is relatively easy. You will not require any adjustment or gapping after your purchase, which is what we liked the most about this product.


  • Easy installation
  • Boost engine performance
  • Delivers the longest & most powerful spark
  • Offers the best access to air/fuel mixture for efficient combustion
  • No gapping or adjustment is required
  • Well reputed brand
  • The yttrium-enhanced ground electrodes reduce wear & boost service life


  • Comes only in the pack of one
  • Designed for use in the US only

4. NGK Iridium IX Spark Plugs With Gasket-Sealing & Anti-Corrosion Properties

best spark plug for 2 stroke engines
  • Brand- NGK
  • Core Material- Iridium
  • Top Material Type- Metal
  • Item Weight- 6.4 ounces
  • Vehicle Service Type- Universal
  • Comes with a trivalent metal layer offering anti-corrosion & anti-seizing properties
  • The high flammability of iridium IX makes it ideal for handling temperature changes
  • It comes with gasket-sealing properties
  • The ribs on the body cockle to extinguish the fire
  • Offer excellent fuel economy, Easy to install

Another best spark plugs for a mercury 4-stroke outboard that you can purchase in 2023 are from NGK. This product offers universal usage across different 2-stroke and 4-stroke outboard engines and comes in packs of one and four.

The spark plugs are made from iridium IX, ensuring high-end performance with impressive ignitability and boosted throttle response.

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The tip of the plug is laser welded and made of iridium. Iridium gives you high durability and a stable, consistent spark, as its flammability is relatively high. In addition, the metal plating on the surface offers corrosion resistance.

The corrugated ribs and longer insulator nose work well in preventing flashover. Also, the triple gasket seal eliminates any chance of gas leakage. Overall, this product is a safe choice you can opt for.


  • Comes with a trivalent metal layer offering anti-corrosion & anti-seizing properties
  • The high flammability of iridium IX makes it ideal for handling temperature changes
  • It comes with gasket-sealing properties
  • The ribs on the body cockle to extinguish the fire
  • Offer excellent fuel economy
  • Easy to install
  • Available in packs of four and one


  • The iridium dust is flammable
  • A little pricier than similar products in the market

5. Quicksilver Pre-Gapped AC Delco MR43T Spark Plug

yamaha 2-stroke outboard spark plugs
  • Brand- Quicksilver
  • Core Material- Copper
  • Top Material Type- Nickel
  • Item Weight- ‎1.44 ounces
  • Product Dimension- ‎5.9 x 4.7 x 2.9 inches
  • Vehicle Service Type- Watercraft
  • Durable
  • Good construction quality
  • Come pre-gapped
  • The nickel chrome alloy sheathing provides protection from corrosion
  • Offer good performance
  • Specially designed for endurance, durability, and efficiency

Another product that is an ideal purchase if you are specifically looking for spark plugs for a 50 hp mercury outboard 2 stroke is Quicksilver AC Delco MR43T. This product comes in a pack of one. Its copper core, nickel alloy tip, and ribbed suppressor seal offer high durability and performance.

The nickel chrome alloy sheathing on the exterior and the center electrodes helps prevent corrosion and even resist wear & tear from spark erosion.

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The plug comes pre-gapped and works well in preventing misfires. The copper core electrode offers better heat transfer to the tip, making it a reliable replacement for factory-installed spark plugs.

Like most other products on this list, this product has multiple applications. You can use it in your car, motorbike, boat, garden machinery & more. You can use this product to boost your engine’s ignition and overall performance at cheap rates.


  • Durable
  • Good construction quality
  • Come pre-gapped
  • The nickel chrome alloy sheathing provides protection from corrosion
  • Offer good performance


  • Can not handle the pressure well
  • A few customer complaints regarding the plugs blowing up

6. Champion 810 Simple Yet Effective Compact Spark Plugs

best spark plug for motorized bike
  • Brand- Champion
  • Core Material- Copper
  • Top Material Type- metal
  • Item Weight- ‎‎2.39 ounces
  • Product Dimension- ‎0.5 x 1 x 3 inches
  • Easy installation
  • Simple yet effective
  • Offer good performance

Champion 810 spark plugs come in a pack of two. These authentic products are made of copper in their core and metal in the exterior.

The copper core electrode enhances conductivity and temperature handling, offering longevity. You can use it for your automobiles and other motorized equipment, like boats, lawnmowers, & more.

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This product may seem pricey to a few customers, but it should be fine as you get high-end quality. Furthermore, the manufacturer offers a two-year company guarantee or 20k miles on usage to secure your purchase.


  • Easy installation
  • Simple yet effective
  • Offer good performance


  • Small size compared to other products on this list

7. NGK Standard BPR6ES Spark Plug With Corrosion Resistant Zinc-Dipped Shell

Best spark plugs for mercury 2 stroke outboard
  • Brand- NGK
  • Core Material- Copper
  • Top Material Type- Metal
  • Item Weight- ‎‎2.4 ounces
  • Product Dimension- ‎‎3.4 x 0.8 x 0.7 inches
  • Vehicle Service Type- Universal
  • Solid construction
  • Dual ground electrodes offer consistent spark
  • Triple gasket seal prevents combustion gas leakage
  • The zinc-dipped shell makes the plugs corrosion-resistant
  • These prevent flashover with the help of corrugated ribs
  • Comes in a pack of four

Our final pick for the best spark plug for motorized bikes and engine-driven machinery is standard BPR6ES by NGK. It is made of a solid copper core that offers instant spark, better heat dissipation, and heat conductivity.

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The plug has dual ground electrodes that offer a more consistent spark for ignition. We really like the nose of the plug. It is longer, well insulated, and prevents fouling under all circumstances.

In addition, there are corrugated ribs on the insulated nose that prevent flashover. Furthermore, the plug comes with a triple gasket seal which works well in eliminating the leakage of combustion gas.

Lastly, the outer shell of the plug is zinc dipped, making the product corrosion-resistant.


  • Solid construction
  • Dual ground electrodes offer consistent spark
  • Triple gasket seal prevents combustion gas leakage
  • The zinc-dipped shell makes the plugs corrosion-resistant
  • Comes in a pack of four


  • It can be too big for some automobiles

Things To Consider When Buying The Best Spark Plugs For 2 Stroke Outboard

Only finding out the faulty spark plugs in your vehicle is not enough. To ensure your ride runs smoothly, you must replace the faulty ones with the right ones.

But markets are filled with different products, making it challenging for buyers, especially first-timers, to find the best spark plug for 2-stroke engines.

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Finding the ideal spark plugs for your vehicle might be difficult but not impossible. You can quickly become a pro buyer with the proper knowledge and guidance.

To help you get started, our experts have listed some crucial features or factors you must go through to make a worthy purchase.

A. Size

Before buying a product, you must check whether it is compatible with your ride. A product might be all good, but it is only helpful if your ride can accommodate it.

So, check for the size and compatibility of a product with your ride and engine model before purchasing.

B. Durability

No one likes to spend their hard-earned money frequently on cheaper goods. If you wish to avoid replacing your spark plugs frequently, look for the ones that can withstand harsh circumstances well, offering longevity. A product on which you can depend is the right one.

C. Sales Position

Another great way to separate good mercury outboard spark plugs from bad ones is by checking their sales position in your region.

The products in high demand are more likely to be of good quality. People mostly go crazy over automobile parts that give the required results.

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The increase in demand for a product indicates it is a successful one. Also, as the demand grows, the manufacturer is more likely to work on boosting the product’s quality and offer customers a better support system.

D. Availability

Automobile products get updated frequently. Every now and then, as per the product’s performance and customer feedback, companies replace the older models with new ones.

So, ensure you are buying the latest and updated model that will be readily available for future purchases.

E. Customer Reviews

You can always turn to the internet to know how well a product works. Look for online reviews of the product before buying. Knowing what fellow buyers say about it can tell you if it is worth buying.

Drop the product with a high proportion of negative reviews or positive reviews. Products with a perfect blend of good and bad reviews are better than others.

F. Brand Reputation

We all prefer to buy things from a brand we are familiar with. Several brands in the automotive world make and sell mercury 2-stroke spark plugs.

But the catch is that not all of them are good quality or worth your money. You can filter out the good brands from the bad ones by exploring their reputation in the market.

The brands offering high-end quality products will likely have a long list of satisfied customers and repurchasers.

You can explore the internet and learn about their position in the market. You only need to remember that you will have to pay more for a good quality product than a bad one.

G. Cost

Finally, you need to look at the cost of the product. Assuming costly is good and cheaper is worse is not the right buyer attitude.

Set up a budget and find a good quality product under it. Good quality spark plugs can save you a lot in the long run.

Top FAQs About Best Spark Plugs For Mercury 4-stroke Outboard

What Makes Spark Plugs Go Bad?

The only reason spark plugs stop working is due to the extreme wear and tear they face.

And one of the common reasons for this extreme wear & tear is the buildup of oil and carbon that, over time, dulls the effectiveness of the plugs.

Other than this, things like constant overheating of spark plugs due to incorrect fuel-to-air ratio, poor fuel quality, and lousy fuel filters also cause spark plugs to deteriorate.

Apart from all these, another reason why your spark plugs may start causing problems is a loose wire connection or improper engine tuning.

So, if you wish to increase the usage period of your spark plugs, keep an eye on these signs and make it a routine to check them weekly.

What are the symptoms of bad spark plugs?

Driving your vehicle with bad spark plugs can adversely affect your ride’s performance.

Apart from this, your engine can suffer immensely. You could experience things like:

  • Rough starts
  • Bad acceleration
  • Reduced gas mileage
  • Engine misfires
  • Rough idling

So, if you experience any of these things happening in your ride, you should inspect the spark plugs as soon as possible.

How can I replace spark plugs?

If your engine’s spark plugs have gone wrong, you need to replace them immediately to prevent any damage to your engine.

Replacing spark plugs is easy. If you know a little of handy work, you can easily do the job at home alone.

All you need to do is follow the steps carefully. Below is our step-by-step guide that can help you:

  • First, ensure the engine is cold.
  • Disconnect the electrical connectors from the ignition coils.
  • Remove the ignition coils.
  • Examine the spark plugs. If there is any dirt & debris inside the plugs, remove it using compressed air.
  • Unscrew the plugs using a ratchet.
  • With the help of a gap gauge, check the electrode gap. Assure the gap in the plugs is as per your engine.
  • Simply place and screw the new spark plugs by hand and then tighten it further with the help of a torque wrench.
  • Reinstall the ignition coil carefully, along with their electrical connectors.
What are the e3 spark plugs’ pros and cons?

E3 Spark Plugs is a well-known and well-reputed auto part brand in the USA.

It is currently prevalent for its spark plugs, which enhance your vehicle’s overall performance.

This brand’s most popular spark plugs are made of copper and alloy steel. Copper is the core material, whereas the exterior is alloy steel.

The plugs come pre-gapped, eliminating the need for you to do it. The universal application makes the spark plugs ideal for cars, motorbikes, boats, lawnmowers, snowblowers, and other similar machinery.

Which type of spark plug should I use in my car?

If it is your first time purchasing spark plugs, you will find four main types: copper, indium, platinum, and double platinum.

Mostly, all the spark plugs have similar internal compositions, but they all differ in tip construction. The tip of the plug is where the spark happens. Thus it is the part that makes all the difference.

Always refer to the owner’s manual to ensure you are buying the right product for your ride. It will tell you the ideal type & size for the replacement.

You can always choose the type of plugs as per your preference. If you wish to go for platinum instead of copper (like in your user manual), you can.

But ensure you always go for the higher quality, not the lower one.

For Example: Going for iridium instead of platinum is right. But going for copper instead of platinum is not a wise choice.

Which spark plug construction material is the cheapest?

If you can not afford to spend handsomely on your spark plug purchase but still want to get the good ones, you can always go for the ones with copper construction.

Copper is the least expensive spark plug building material. The products with copper construction have a tip made of copper, which is highly conductive and offers a vital spark for ignition.

However, when it comes to endurance, copper is a soft metal. It erodes away quickly due to all the heat & pressure applied to it.

You can quickly expect a copper plug to last around 20,000 to 30,000 miles.


If you wish the engine of your ride and other engine-driven machinery to work smoothly, you must take better care of all its parts, including spark plugs.

Finding the right product for your engine can be overwhelming. Still, with this easy guide, you can purchase the best spark plugs for mercury 2-stroke outboard.

Go through the buying guide and explore each product to find the most suitable item per your requirements.

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