In order to avoid this, we have to bear in mind some pointers about this motorcycle parts.

First, always go with the motorcycle parts manufacturer’s recommendations. That way, you can never go wrong.
Second, if you have qualms over the parts, call the manufacturer to save you from further trouble. Do not experiment with parts, especially if you have little knowledge about them. They can go wrong in just a flick of the finger and can catch you off guard without any assistance and remedy.

For instance let us consider common motorcycle plug number: DPR9EA-9. This is a 12 mm thread 18 mm plug socket, P stands for projected electrode, R for resistor, heat range 9, E for 19mm thread reach, A for specials and 9 for .9mm plug gap. The next suffix letter is for thread reach. It can make you come unstock. If you put a plug with a too long thread reach then it puts a motivating impression in the top of the piston, if it is otherwise, it will not reach inside the combustion chamber. The next letter is again for construction features. There may appear another number after it. It refers to the plug gap which it is set at.

NGK plugs are good. The first letter prefix stands for the thread type and socket hexagon size. Their size ranges from 14mm thread to 8mm on the little 4 cylinder 250 imports. The second and third letter prefix refers to the construction feature.

With this kind of spark plugs it should be known that the higher the number the colder the plug. What’s the significance? Well, racing bike engines use cold plugs because they generate enormous heat. On the other hand, if fowling is one of your problems, use a hotter plug. Remember though that other motorcycle spark plugs have inverted heat range. Just consult the manual or your manufacturer to be sure that you are getting the right plugs.

If you are confused, you can always go back to the first rule – Follow your bike manufacturer’s recommendations. That rule saves!