In the area of scooters with relatively low capacities and high revs, high demands are made of the spark plugs. Overheating with the risk of the sticking or sooting up of the spark plug are frequent problems with the incorrect choice of spark plug.
Spark plugs are available with different thermal values (stated as a figure in the type code and different from one manufacturer to the next), materials (e.g. copper, silver, platinum) as well as in certain standard unit sizes (which differ in terms of length, diameter and thread). Interference-suppressed spark plugs are a good idea with usage of rev counters i.e.. Also radio frequencies of mobile phones, radios etc. are not affected. They are not recommended with weak ignitions, however. They are marked with a "R" in the item description.
Colder spark plugs are suitable for racing cylinders and use over long distances. In this context, the sound thermal output of heat to the cylinder head takes place, there is a risk of sooting, however.
Hotter spark plugs are used in sport and standard cylinders. The reach their operating temperature quickly but can also overheat.
Most spark plugs for scooters have a M14x1.25 SW 20.8 thread and are either long thread (19mm) or short thread (12.7mm). Please note: putting a long thread spark plug in a short thread cylinder head will damage the piston.
We only stock high quality spark plugs from BOSCH, DENSO and NGK in our product range. BOSCH is a German manufacturer while NGK and DENSO are Japanese.
Conclusion: regular exchange/replacement is compulsory. Spare spark plugs belong in every luggage compartment.
SIP TPP: order a new ignition cable and new spark plug socket at the same time. All required information on spark plugs with a description of thermal value, spark plug designations, interference resistance and a comparison of the manufacturers is available both at www.sip-scootershop.com and as a PDF download. Further types of spark plug are also provided here.