Engine Adjustments - Westerbeke 5.0KW BCG-60Hz Service Manual

ENGINE ADJUSTMENTS
ENGINE COMPRESSION TEST
1. To check the engine's compression pressure, warm up the
engine then shut it down.
2. Remove the three spark plug caps and remove the three
spark plugs.
3. Install a compression adapter and gauge in the spark plug
hole.
4. Close the raw water seacock.
5. Crank the engine with the start motor and unplug the
ignition coil and allow the compression gauge to reach a
maximum reading and record.
6. Measure the compression pressure for all the cylinders.
Ensure that compression pressure differential for each
cylinder is within the specified unit.
COMPRESSION PRESSURE 189PSI (1260 Kpa) at 400 RPM
Compression Pressure should not differ by more than 14 psi (100Kpa)
7. If a cylinder's compression or pressure differential is
below the limit, add a small amount of engine oil through
the spark plug hole and repeat steps 4 and 5.
a) If additional oil causes an increase of pressure, the
piston ring and/or cylinder wall may be worn or damaged.
b) If additional oil does not increase compression
pressure, suspect poor valve contact, valve seizure, or
valve wear.
8. Reinstall three plugs and ignition wires.
9. Open the raw water seacock.
COMPRESSION
GAUGE
TESTING ENGINE
~ ~COMPRESSION
~
ADAPTER
NOTE: Do not guess the conditions of other cylinders from a
result of testing one cylinder. Be sure to measure the
compression pressure for each cylinder. Look for cylinders
with dramatically (at least 20%) lower compression than the
average of the other cylinders.
If
the weak cylinder is flanked
by healthy cylinders, the problem is either valve or head-
gasket related. very low compression in an adjacent cylinder
indicates gasket failure. Abnormally high readings on all
cylinders indicate heavy carbon accumulations, a condition
that might be accompanied by high pressure and noise.
TESTING OIL PRESSURE
To test oil pressure, remove the hex head plug from the oil
gallery and install a mechanical oil pressure gauge in its
place. After warming up the engine, set the engine speed at
1800 rpm and read the oil pressure gauge.
OIL PRESSURE BETWEEN 30 AND 40 PSI AT 1800/1500 RPM
NOTE: A newly staned, cold engine may have an oil pressure
reading up to 70 or 80 psi. A warmed engine can have an oil
pressure reading as low as 30 psi. Oil pressure will vary
depending upon the load placed on the generator.
OIL GALLERY
HIGH TENSION CORDS (IGNITION WIRES)
Check the ignition wires every 500 operating hours as engine
compartment heat can deteriorate the wires.
Check the resistance of each wire. Do not pull on the wire
because the wire connection inside the cap may become
separated or the insulator may be damaged. When removing
the wires from the spark plug, grasp and twist the moulded
cap, then pull the cap~ff the spark plug.
THE RESISTANCE VALUE IS 410 OHM PER INCH OF WIRE.
TESTING
RESISTANCE
Engines & Generators
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