Motorcycle Spark Plugs Spark plugs have to withstand temperatures far in excess of 2000°C and pressures of 70 bar and above in the engine's combustion chambers, not to mention the chemical stress resulting from the combustion process. So it's no wonder that they eventually wear out. When the time comes, you should always use high-quality replacement spark plugs. If you shop at Louis, you can be sure that the spark plugs you buy will give you long and reliable service. The Louis Bike Database shows you which spark plugs you need for your machine.