O.S. Engines 91SZ-H - Manual (Page 4)

6
Notes on installing cooling fan and clutch
Do not use a tool which
locks piston when
installing a cooling-fan
and clutch, or top of
the piston may be
damaged. Also, do not
insert a screw driver or
the similar into the
exhaust port.
It is recommended to use Crankshaft
Clamp 91 (Code No.71530510) available as
an optional tool.
It is made of durable engineering plastic
and locks the crankshaft without risk of
damage to any part of the engine.
Application is as follows:
Remove the crankcase rear cover plate from the
engine and rotate the crankshaft to the bottom
dead center (BDC) position.
Insert the crankshaft clamp so that its grooved
portion surrounds the crankpin and lower end of
the connecting rod and securely tighten the fan
or clutch onto the crankshaft.
Insert this groove onto
the connecting rod.
BDC position
Rotate the crankshaft so that the
connecting rod comes to this position.
7
NOTES WHEN APPLYING AN ELECTRIC STARTER
Because of this initial tightness, a
standard electric starter may have
difficulty in rotating the engine when
cold, before it has been adequately
run-in. In this case, use a high-torque
type starter.
Do not over-prime. This could cause
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 pumped out fuel from
getting into your eyes.