WASHER 6H0190 - Caterpillar

Ignition systems can cause electrical shocks. Avoid contacting the ignition system components and wiring.Do not attempt to remove the valve covers when the engine is operating. The transformers are grounded to the valve covers. Personal injury or death may result and the ignition system will be damaged if the valve covers are removed during engine operation. The engine will not operate without the valve covers.
Maintenance of the spark plugs is required in order to achieve the following benefits:
Normal fuel consumption
Normal level of emissions
Maximum service life of the spark plugs
Stable operationThe service life of the spark plugs is affected by fouling due to deposits from the oil and by peak voltage. Maintenance of the ignition system is also affected by voltage. Higher voltage is required by higher inlet manifold air pressure, a higher compression ratio, and a leaner air/fuel ratio. Higher voltage reduces the service life of components such as spark plugs, wires, and transformers.Removing the Spark Plug
Standard Ignition System
Illustration 1 g00798356
(1) Wire for the secondary circuit
(2) Transformer assembly
(3) Boot
(4) Seal
(5) Spark plug
(A) Section view of boot
Pulling on the wiring harness may break the wires. Do not pull on the wiring harness.
Disconnect wire (1) from transformer assembly (2). The wire may break if you pull on the wire.
Remove boot (3).
Pressurized air can cause personal injury. When pressurized air is used for cleaning, wear a protective face shield, protective clothing, and protective shoes.
Ensure that the area around the spark plug is clean and free of dirt and debris.