NGK BR7HS replacement spark plug to fit a wide range of 50cc 2-stroke scooters. Please check your owner’s manual to verify compatibility before purchasing. NGK is one of the world’s leading spark plug manufacturers. As the factory choice of many vehicle makes, NGK is there when the spark starts to fade. You get a standard NGK spark plug, the same as the one installed in your vehicle. The calorific value and construction of the plug are the same as the original. Spark plug life is affected by fuel type, engine condition, driving time and engine temperature. On 4-stroke engines over 250cc, spark plugs should be cleaned or replaced approximately every 3,500 miles. On smaller engines, particularly 2-stroke engines, this should be done approximately every 1,500 miles. Oil deposits begin to build up after this mileage and can cause starting problems and reduced performance. The intervals may be shorter if low-quality oil is used or the driving time is very short.