2003 Ducati SuperSport 620 S Owners Manual - Page 137

Cleaning and replacing the spark plugs (fig. 68) Spark plugs are essential to smooth engine running and should be checked at regular intervals. This is done quite easily and quickly and provides a good measure of engine condition. Remove the LH fairing, remove the spark plug caps from the cylinder head using the wrench supplied with the bike. Check the colour of the insulating ceramic material of the central electrode: a light brown, even colour is a sign of good engine condition. If colour has altered or you find any dark deposits, change the spark plug and report this to your Dealer or authorised workshop. Check wear on the central electrode. If it looks worn out or has a vitrified appearance, change the spark plug. Check electrode gap: it should be 0.6-0.7 mm. Important If the gap needs adjusting, be very careful when bending the side electrode. If gap is too wide or too close, engine performance will be affected. This could also cause misfiring or irregular idling. Clean the electrode and the insulating material accurately using a small metal brush and check seal condition. Clean the seat in the cylinder head. Be careful not to let any foreign matters fall into the combustion chamber. Refit spark plug into cylinder head. Tighten until thread is fully into the head. Tighten the spark plug to 20 Nm. If you do not have a torque wrench, you can use the wrench supplied with the tool kit to tighten the spark plug an additional 1/2 turn. Important Never use spark plugs with a heat rating other than recommended or a thread length other than standard. Spark plugs should be tightened properly. E 0,6÷0,7 mm fig. 68 61