O.S. Engines 12TG-PX User Manual
Page 4

6
Piston
Cylinder Liner
Crankshaft
ENGINE CONSTRUCTION
With this engine, the piston
will feel tight at the top of its
stroke (TDC) when the engine
is cold. This is normal. The
cylinder bore has a slight
taper. The piston and cylinder
are designed to achieve a
perfect running clearance
when they reach operating
temperature.
Near TDC
Slight taper
When the engine is cold. When the engine is hot.
7
NOTES WHEN APPLYING
AN ELECTRIC STARTER
Do not over-prime. This could
cause a hydraulic lock and damage
the engine on application of the
electric starter.
If over-primed, remove glowplug,
close needle-valve and apply
starter to pump out surplus fuel.
Cover the head with a rag to
prevent any pumped out fuel from
getting into your eyes.
Remove the glowplug.
Pump out surplus fuel.
Install the glowplug.