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Spark Plug (IFR8H11) (Iridium) for Honda TRX450R

Spark Plug (IFR8H11) (Iridium) for Honda TRX450R


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Every year the range of NGK spark plugs grows to accommodate the ever-increasing demands of modern engines. Spark plug design must take into consideration many features of an engine including physical dimensions, combustion chamber shape, cooling abilities, fuel and ignition systems. Spark plugs play a vital role in producing the maximum power from an engine whilst keeping fuel consumption and emissions to a minimum. Choosing the correct spark plug type will help a vehicle manufacturer meet legislated emission targets and assists the motorist in getting the best from their engine.

Increases in the size and the requirement to improve the cooling of the inlet and exhaust valves have meant that the space available for the spark plug is severely restricted on some cylinder heads. A change in spark plug design, possibly the adoption of a taper seat and extended reach (threaded portion) or even the use of a smaller diameter is often the answer. Some engines require the use of two spark plugs per cylinder and again due to space restrictions these might be of different sizes.

Changes in fuelling systems and the fuel itself have meant some special features being adopted at the ‘firing end’ of the spark plug. Extra projected types push the spark position into the heart of the combustion chamber to promote better combustion of the fuel/air mixture, which is weaker than ever in an effort to improve economy. Modern engine manufacturers often require increased spark gaps to allow a longer spark duration, which again aids more efficient combustion.

To combat the ‘cold fouling’ effect that can occur in some engines using unleaded fuels specially arranged ground electrodes are sometimes used. These can force the spark to discharge across the insulator and thus burn away any built-up carbon that could cause poor starting or misfires. It is not uncommon to find two, three or four ground electrode arrangements in new vehicles. The use of precious metals on the tips of the spark plug electrodes is not uncommon especially on higher performance engines. Whilst these spark plugs do have increased service life, they are often specified because of their superior ignition qualities.

Our engineering departments work very closely with the engine and vehicle manufacturers to produce the ideal spark plug type for each application. Any change in production is expensive for a manufacturer and therefore new spark plug types are only produced where necessary. NGK employ the very latest production technology to ensure that every aspect is catered for – performance, economy and value.

The Iridium IX spark plug benefits from the use of the precious metal Iridium on its centre electrode. Iridium is harder than other precious metals used in spark plug manufacture, has an extremely high melting point and offers greater protection from chemical attack. These features allow the use of an extremely small diameter electrode (0.6mm) without compromising the spark plug’s service life.

When compared to nickel plugs, service life is greatly extended. Combined with the use of the taper cut ground electrode this spark plug has superior gas flow properties and lower voltage requirements, which offers further improvements in starting, idling and throttle response.

Iridium spark plugs are used in many high-performance engines and in competition.

Owners who want the very best performance will want the best spark plug we can offer with Iridium IX.

Compatible with:
Honda TRX450R Sportrax ’04-‘05

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