How long do motorcycle spark plugs last?

With so much information being available from the spark plug manufacturers, are you confused? How do you know if your spark plug is suitable or not? When should you change your spark plugs?

Don’t confuse a car and motorcycle spark plug lifespan. Motorcycle spark plugs have a life of around 12,000 miles, so it’s good practice to change your spark plugs at 10,000 miles. However, if your spark plug fails, your recovery costs could be expensive.

How often should you change spark plugs on a motorcycle?

It depends on how often you use your motorcycle. Is there a time, or does it rely on the number of miles you cover? 

It’s a mileage thing; if you use your motorcycle frequently, it makes perfect sense to treat your spark plugs as a serviceable item and not wait for them to fail.

Once your motorcycle is hitting the next 10.000 miles, change your spark plugs if it coincides with an oil change and general service all the better.

There is an amount of confusion generated by the manufacturers of spark plugs to the lifespan of the spark plug itself. It is fair to say if you have a premium spark plug, you should still adhere to the average life and change your spark plugs at 10,000 miles.

Is this wasteful? You could argue that changing your spark plugs too early costs you extra cash. However, do you wait for your oil to deteriorate to the very limits of its properties? No, and the answer is why it would damage your engine.

Although a faulty plug will not harm your engine, it could cause a breakdown and the need to be recovered from the roadside. It’s an expensive day.

Changing your spark plugs at 10,000 miles will keep your spark and ignition in tiptop condition, reflecting on the performance of your motorcycle.

How do I know if my motorcycle spark plugs are bad?

The symptoms of bad spark plugs are evident and worsen as the spark plugs deteriorate further.

  • A common sign of a deteriorating spark plug is a misfire or misfiring.
  • Backfiring is also a ubiquitous symptom of a bad spark plug.
  • A flooded engine due to the fuel and air mixture entering the cylinder is not ignited. This will also give a strong smell of petrol.
  • Due to incomplete combustion, your expensive petrol will be spraying out of your exhaust pipes.

When these symptoms exist, it is evident you need to change your spark plugs. Other signs are possible to check engine light on.

Rough idling is a classic symptom of a bad spark plug together with an increase in emissions from your exhaust. Bad spark plugs are unmistakable hence the need for adhering to a replacement schedule.

Another symptom is bad fuel economy; bad spark plugs are not igniting fuel; instead, your fuel is being sent straight to your exhaust pipe where it can ignite and backfire or spray to the atmosphere.

You may find your engine runs so rough it knocks due to bad spark plugs.

How often should iridium spark plugs be replaced?

Iridium and platinum-tipped spark plugs are long-life spark plugs and expensive ones!

It would be reasonable to expect the life of the spark plug to be in line with manufacturers guidelines, but, with everything, there is always a caveat.

Suppose you ride your motorcycle like a gentleman and take it generally easy to enjoy the experience of the motorcycle. In that case, the life could be extended to twice as much as you would expect from a standard premium spark plug.

However, if you have a sports motorcycle, then the game changes if you ride like Valentino Rossi every day of the week.

Iridium plugs are long life and high-performance plugs giving a guaranteed vital spark that will increase the performance of your motorcycle.

Pushing your motorcycle to high revs will impact the longevity of your plugs and other serviceable components. It only makes sense to realise that the more complex you ride, the more wear and tear on the components of the motorcycle.

 Do iridium spark plugs go bad? Yes. Motorcycle engines are different from car engines. Sports bikes have mainly four-stroke engines hence four spark plugs.

Apart from the extra 45 pounds, you will pay for the spark plugs. Your engine can run very hot. If your motorcycle is running lean, it can reach 800 celsius.

Now here is the problem: the plug’s insulator is not designed for these kinds of temperatures, so iridium plugs frequently fail on some higher-end motorcycles.

If it’s not the insulator, it’s the gap. The gap widens due to the increased temperature. Remember, motorcycle engines run hotter than car engines.

Back to the original question, given what you know now, if you ride a sports motorcycle, ask yourself if Iridium tipped spark plugs will give you an extra gain and what is the cost of the spark plugs over the actual lifetime.

For the average day-to-day motorcycle rider, the decision to purchase Iridium spark plugs is mainly down to available cash in your pocket.

Will your performance increase? Yes. Do you need more performance? Only you can answer that question.

How long does NGK spark plugs last in a motorcycle?

The answer to this question is not easy to answer. It depends on your motorcycle and the riding style of the owner.

NGK/NTK spark plugs are ubiquitous for a good reason. They are great for spark plugs and work perfectly well in almost every application.

Treat your spark plugs as a serviceable item as you would your oil and brakes if you are a frequent rider. Change the plugs every 10,000 miles or, at the very least, inspect the plugs and reset the gap for optimal performance.