
4
User’s Handbook, TSL 4230, Issue 4
35
4016-E61TRS
How to clean, set and fit a spark plug
Special requirements
1 Clean any carbon/ash deposits from the spark plug thread and ceramic insulator using a suitable solvent
and a dry cloth.
Note: A light coating of ash evenly deposited on the electrodes indicates the plug is in good condition with a
clean burning mixture.
2 Clean any loose ash deposit from the end of the spark plug (A1) using a nylon brush.
Caution: Do not use a metal brush to clean a spark plug as the porcelain around the centre electrode will be
scratched allowing ash deposits to build rapidly on the roughened surface causing plug failure.
3 Set the spark plug gap to 0,25 mm (0.010 in) (A2).
Note: The centre and ground electrodes of the spark plug are tipped with a hard surface which must not be
filed or cleaned using abrasive paper.
4 Every time a spark plug is refitted the sealing washer (A3) must be renewed. Use sealing washer part
number Y98/00038.
Caution: The spark plug should be finger tightened into the cylinder head, if resistance is felt clean the plug
thread in the cylinder head using a thread chaser. Never use a thread tap.
5 Apply a very small amount of Poly Butyl Cuprysil grease to the thread of the spark plug (A4).
6 Fit the spark plug carefully locating it in the cylinder head. Tighten down finger tight, then torque to 50 Nm
(35 lbf ft).
7 Refit the ignition coil (B3) and tighten the retaining nuts (B2) to 13,5 Nm (10 lbf ft).
8 Refit the power lead (B1).
Special tools
Description
Part number
Cylinder head spark plug thread cleaning
tool
27610178
This document has been printed from SPI². Not for Resale