Injection Pump Chain Wheel; Oil Pressure Relief Valve - Westerbeke WPDS-20 Technical Manual

A22
INJECTION PUMP CHAIN WHEEL
1. If the chain wheel bearing requires renewal (see
Data). remove the driving flange from the chain
wheel.
2. Press out the old bearing and press in a new bearing
from the chamfered end of the chain wheel bore.
3. Finish the bore ofthe new bearing to the size given
in Data.
4. Fit the driving flange to the chain wheel with the
master spline and timing mark in the relative
positions shown in Fig. 1. Position the flange so
that its securing bolts are central in the adjusting
slots.
Data
Chain wheel bearing bore (finished in position) ..
Clearance on chain wheel hub
Fig. 1
1·75025 to 1·75075 in. (44·46 to 44·47 mm.)
·001 to ·002 in. (·03 to ·05 mm.)
OIL PRESSURE RELIEF VALVE
1. Unscrew the plug shown in Fig. 1 and withdraw
the relief valve spring.
2. Remove the valve cup. using tool18G 69.
3. If the valve cup to seat contact is unsatisfactory. lap
the valve cup onto its seat with tool18G 69.
4. Renew the valve spring if it is not as specified in
Data.
5. Reassemble the components to the crankcase.
Data
Free length of oil pressure relief valve spring
Operating pressure ..
Fig. 1
3 in. (76·2 mm.)
50 to 55 Ib./sq. in. (3·52 to 3·87 kg.Jcm.
2 )