Maintenance Spark Plugs Before installing new spark plugs, always check for proper type and gap 1 . Incorrect spark plugs can cause operational problems and possible internal engine damage. Before installing a spark plug, the spark plug seat in the cylinder head should be wiped clean. Tighten plugs to the proper torque value 1 . Make sure the spark plug terminals are fully seated on the spark plugs. 23172 When spark plug leads are removed, be sure they are replaced in the correct firing order 1 . DANGER! Avoid abusive handling that could crack the spark plug’s ceramic body ( A ).
Damaged spark plugs can emit external sparks that could ignite any fuel vapors in the engine compartment, resulting in fire or explosion. 7743722 - Downloaded from www.volvopenta.com 13/05/2008 20:17:06 Do not operate engine if spark plug boots or high-tension leads are torn or cracked. This con- dition could allow external sparks which could ignite any fuel vapors in the engine compart- ment, resulting in fire or explosion. Checking and Changing Spark Plugs CAUTION!
To prevent possible injury caused by someone inadvertently starting the en- gine, remove the ignition keys from each starting location (especially if the engine room/engine compartment cannot be seen from various remote starting positions such as a flybridge or enclosed cabin). 1. Twist and pull only on the spark plug wire boot (pulling on wire may cause separation of the core of the wire). 2. Remove spark plugs using a 5/8-inch spark plug socket or a 5/8-inch box wrench. Use care to avoid cracking the spark plug insulators ( D ). 3. Carefully inspect the insulators and electrodes of all spark plugs.
‰ Replace any spark plug which has a cracked or broken insulator or which has loose elec- trodes ( B ). ‰ If the insulator is worn away around the cent- er electrode ( C ), or the electrodes are burned or worn, the spark plug is worn out and should be discarded. 23172-1 ‰ Spark plugs that are in good condition, except for carbon or oxide deposits, should be thor- oughly cleaned and gapped. 1. For additional information, see Technical Data on page 113. VPA 7743722 English 10-2004 79