spanner, prevents the plug from falling out of the spanner when removing or replacing the plugs.
Suitable 3/8in. dia. flexible shaft can be obtained from B. 0. Morris Ltd., Briton Road, COVENTRY, or other manu-facturers of flexible drive shafts.
Cleaning
Clean the plugs on a sand blast cleaner, followingthemanufacturer’s instructions. Do not prolong the use of the abrasive blast as it will erode the insulator. Re-move carbon and other deposits from the threads with a stiff wire brush. Any deposits will retard the heat flow from the plug to the cylinder head causing spark plug overheating and pre-ignition. Clean the electrode surfaces with a small file. Dress the electrodes to secure flat parallel surfaces on both the centre and side electrode (see Fig. 102).
Inspection
After cleaning, examine the plug care-fully for cracked or broken Insulators, badly pitted electrodes, and other signs of failure. Replace as required.
Adjustment
Set the spark plug to the gap setting given, in the Data Section under “Ignition” by bending the ground elec-trode (see Fig. 104).
To refit
Install the spark plugs. The tightening torque equivalent is 15-20 ft./lbs. Connect the spark plug wires. Push all weather seals into position. The H.T. lead wire runs are shown In Fig. 105.
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