O.S. Engines 21RZ-V01B (P) - Manual (Page 12)

FURTHER PRECAUTIONS
When removing the air cleaner, check the inside of the
center tube and carburetor venturi. If any dirt is
detected, this indicates that the filter element was
incorrectly installed or should have been replaced
earlier.In this event, it is vitally important to wash out
the inside of the engine thoroughly, with alcohol or
fuel,before it is used again, otherwise rapid wear of
the piston, cylinder,bearings, connecting-rod, etc., will
occur. Obviously, it will be necessary to carry out the
same procedure with the air cleaner and to replace the
filter element.
NOTE: Be careful not to splash alcohol or fuel
over the filter element, or the filter oil will be
diluted, and the filter capacity lowered.
GLOWPLUG
The role of the glowplug
Glowplug life
Particularly in the case of very high performance engines,
glowplugs must be regarded as expendable items.
Install a plug suitable for the engine.
Use fuel containing a moderate percentage of
nitromethane unless more is essential for racing
events.
Do not run the engine too lean and do not leave the
battery connected while adjusting the needle.
However, plug life can be extended and engine
performance maintained by careful use, i.e.:
With a glowplug engine, ignition is initiated by the
application of a 1.5-volt power source. When the
battery is disconnected, the heat retained within the
combustion chamber remains sufficient to keep the
plug filament glowing, thereby continuing to keep the
engine running. Ignition timing is 'automatic' : under
reduced load, allowing higher rpm, the plug becomes
hotter and, appropriately, fires the fuel/air charge
earlier; conversely, at reduced rpm, the plug become
cooler and ignition is retarded.
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Since the compatibility of glowplug and fuel may have
a marked effect on performance and reliability, it may
be worthwhile to choose the R/C type plug found
most suitable after tests.Recommended O.S. plugs
are A5 and No.8. Carefully install plug finger-tight,
before final tightening with the correct size plug
wrench.
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