Valve Clearance Adjustment; Engine Compression - Westerbeke 5.0KW BCD Operator's Manual

ENGINE ADJUSTMENTS
VALVE CLEARANCE ADJUSTMENT
NOTE: Retorque the cylinder head bolts before adjusting the
engine's valves. See TORQUING THE CYLINDER HEAD
BOLTS.
A
WARNING:
Adjust the valve clearance when the
engine Is cold. Valves are adjusted by cylinder In the tir-
ing Drder Df the engine. Tighten the cylinder head bolts
to the specified torque betore adjusting the valves.
Pull off the air breather pipe from the rocker cover and take
off the rocker cover bolts and the rocker cover to expose the
rocker shaft and valve assembly.
Remove the glow plugs from each of the cylinders to enable
the crankshaft to be easily rotated by hand to position each
cylinder for valve adjustment.
Valves·are adjusted with the cylinder in the piston being
adjusted at Top Dead Center (TDC) of its compression
stroke. Each cylinder is adjusted following the engine's firing
order (1-3-2 for WESTERBEKE three cylinder engines).
Valve adjustment beginning with cylinder #1. Rotate the
crankshaft slowly and observe the operation of the valves for
cylinder #1. Watch for the intake valve to open indicating the
piston is on it's intake stroke (the piston is moving down in
the cylinder). Continue to rotate the crankshaft slowly and
look for the intake valve to close. This indicates the piston is
now starting it's compression stroke (the piston is moving up
in the cylinder towards IDC).
Align the IDC mark on the crankshaft front pulley with the
timing marker on the front gear case cover when positioning
the #1 Piston at IDC of it's compression stroke. Confirm this
by rotating the crankshaft approximately 20 degrees before
and after this point and the two valves for the #1 cylinder
should not move.
VALVE CLEARANCE
~
.
~ 0.25 mm (0.010 in)
~ I
COLD ENGINE
~~
Adjust the valves in #1 cylinder for both intake and exhaust.
Proceed to the next cylinder in the firing order.
Rotate the crankshaft 240 degrees in the normal direction of
rotation .and adjust the next cylinder's valves in the firing
order. Rotate the cranKshaft another 240 degrees and adjust
the valves of the next cylinder in the firing order.
Adjust each valve's ciearance by inserting a O.01Oin
(0.25mm) feeler gauge between the rocker arm and the valve
stem. Make sure to adjust all valves while the engine is cold.
Re-install the glow plugs (use anti-seize compound on the
tIn'eads) and assemble the rocker cover and rocker cover
bolts. See TIGHTENJNG TORQUE SCHEDULE in this
manual.
ENGINE COMPRESSION
Check the compression pressure. To do this warm the engine,
remove all fuel injectors, or glow plugs, disconnect the fueJ
shut-off solenoid wire, and install a compression adapter in
the injector hole or glow plug hole. Connect a compression
tester on the adapter and crank the engine with the starter
motor until the pressure reaches a maximum value. Repeat
this process for each cylinder. Look for cylinders with dra-
matically (at least 20%) lower compression than the average
of the others. Compression pressure should not differ by
more than 35.5 psi (2.5 kg/cm2) at 280 rpm.
Standard
compression pressure
398
Ib/in'
at 280
rpm
'(28.0
kg/em')
If a weak cylinder is flanked by healthy cylinder, the problem
is either valve or piston related. Check the valve clearances
for the weak cylinder, adjust as needed and test again. If the
cylinder is still low, apply a small amount of oil into the
cylinder to seal the rings and repeat the test. If compression
comes up - the rings are faulty.
Abnormally high readings on all cylinders indicates heavy
carbon accumulations, a condition that might be
accompani'ed by high pressures and noise.
NOTE: In case of severe vibrations and detonation noise, the
cause may be fuel injector problems, see FUEL INJEC-
TORS. Poor fuel quality, contaminates and loss of positive
fuel pressure to the injection pump will result in injector
faults.
When re-installing the glow plugs use anti-seize compound.
COMPRESSION TESTER
ADAPTER~
:'~~~·.;;,..:r"'':
....
~
-,~r- ~
INJECTOR OR
~---
GLOW PLUG HOLE
Engines & Generators
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