Fitting Colortune To The Engine - Gunson COLORTUNE G4074 Mode D'emploi

1. Before fitting Colortune, start the engine and warm up to normal operating
temperatures, preferably by going for a short drive.
2. To assist with flame visibility, park your car in such a way that the engine is in the
shade, (or you may use the viewerscope attachment).
3. Stop the engine, take care to avoid hot engine parts and brush away any grit from
around the spark plug before removing it.
4. Fit the COLORTUNE in its place. Never over tighten COLORTUNE into the engine
as an adequate gas seal will be achieved even on taper seat applications with little
more than the equivalent of finger tightness. The rubber bush in a normal plug
spanner will not retain the Colortune as the ceramic is smaller. The HT adaptor lead
may be attached and threaded through the plug socket or viewerscope base to start
the thread. A hexagon adaptor is supplied to adapt larger plug sockets to the
smaller Colortune hexagon
5. If the plug recess is not easily accessible it is wise to apply high melting point grease
to the Colortune washer to help retain it.
6. Screw the plain end of COLORTUNE adaptor lead to the centre electrode of
COLORTUNE. Care should be taken not to over-tighten it or bend the centre electrode.
7. Fit the lower half of the Viewerscope over the lead (if required) pushing the end
down over the hexagon. With the adaptor lead to one side, push the upper half of
the Viewerscope into the lower half in such a manner that the adaptor lead emerges
from the slot in the upper half.
8. Plug the other end of the adaptor lead into the plug cap of the car's ignition system.
The adaptor is designed to fit both types of plug cap (with bare thread or clip type
fitting) and fits most ignition systems. Try to keep the leads away from engine parts,
particularly the exhaust and rotating items.
9. Repeat the above steps if using more than one Colortune.
10. Start the engine. All cylinders should now be firing regularly and the combustion
flames should be clearly visible, either directly or in the viewerscope mirror.
Avoid touching ignition parts when the engine is running remember ignition sparks can
jump, particularly if a connection is not secure.
Tightening torque nominal
10mm 0.20Nm - 1.2 ft-lb
12mm 0.24Nm - 1.4 ft-lb
14mm 0.28Nm - 1.6 ft-lb
Test Pressure Non Destructive
Destructive Test Pressure min.
See the following sections for adjustments and fault diagnosis

5. Fitting Colortune to the engine

34 Bar
95 Bar
5000psi.
12000psi.
9