No one will argue that choosing the right spark plug is important. How can a person, even one far from technology, choose the right candle in the store?
Let's say right away: it is better to navigate using the catalog. It will quickly give you the name you want - for example, BCPR7ES? 11 from NGK. In some cases, information from the instructions attached to the machine helps, but she is not a know-it-all: as a rule, she is not familiar with new developments and most often strives to communicate some kind of abstruse code according to the classification of the manufacturer.
The appearance of the spark plug, unscrewed from the engine as a reference sample, will only help to compare the dimensions of the turnkey hexagon and evaluate the threaded part. Both must necessarily correspond to the original.
In the candles of modern engines, the range of glow numbers is gradually decreasing - the once almighty parameter determined by the temperature regime of the engine. Recently, the fuel combustion process has been actively optimized and the thermal conditions in different engines are becoming close. Therefore, the assortment of candles, differing in glow number, has significantly narrowed.
It is better to refuse all kinds of prechamber candles, no matter how tempting references to Formula 1 are. At high revs, they can give a certain increase in power, but they do not like idling and low loads. With the throttle valve tightly closed, the speed of the mixture in the cylinder is so low that it is not enough for normal ventilation of the inner chamber of the spark plug.