Ignition Timing; Valve Clearance; Compression Test - Westerbeke 8.0KW-60Hz Service Manual

ENGINE ADJUSTMENTS
ENGINE COMPRESSION TEST
1. To check the engine's compression pressure, wann up
the engine then shut it down.
2. Remove the spark plugs and install a compression
adapter (screws into a plug hole) with a gauge.
3. Close off the raw water intake seacock.
4. Crank the engine with the start motor and unplug the
ignition coil and allow the compression gauge to reach
a maximum reading and record.
5. Measure the compression pressure for all the cylinders.
Ensure that compression pressure differential for each
cylinder is within the specified unit.
COMPRESSION PRESSURE SHOULD NOT DIFFER BY MORE
TIfAH 14 psi (100Kpa)
6. 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 tom or damaged.
(b)
If additional oil does not increase compression
pressure suspect poor valve contact, valve seizure, or
valve wear.
7. Reinstall the plugs and the ignition wires.
8. Open the raw water thru seacock.
MEASURING
COMPRESSION
IGNmON DMING
.
.
DIAL GAUGE
1. Attach a timing light to the #1 spark plug and mark the
front crankshaft timing groove and the timing mark on the
scale embossed on the engine's front cover.
Each timing mark represents 5·.
2. Start the engine and wann the engine to its normal
operating temperature.
3. Using the timing light, align the timing groove in the front
crankshaft pulley with the proper timing mark on the
ignition timing scale embossed on the engine's front cover.
Do this by loosening and slowly rotating the
distributor body. Refer to the timing specifications:
IGNmON nMING AT 1800 RPM: 211" BTOC
±
1·
VALVE, CLEARANCE ADJUSTMENT
1. Start the engine and allow it to wann up until the engine
coolant reaches operating temperature.
2. Remove all spark plugs from the cylinder head for easy
inspection.
3.
Remove the rocker cover.
4. Align the crankshaft·timing mark with the timing mark on
the front
CRANKSHAFT
PULLEY
5.
Move the rocker arms on the No.1 and No.4 cylinders
up and down by hand to detennine which cylinder has
its piston at the top dead center on the compression stroke.
If both intake and exhaust valve rocker arms have a valve
lash, the piston in the cylinder corresponding to these
rocker arms is at the top dead center on the compression
stroke.
6. Valve clearance inspection and adjustment can
be
performed on rocker arms indicated by the white arrow
mark when the No.1 cylinder piston is at the top dead
center on the compression stroke, and on rocker anns
indicated by the black arrow mark when the No.4 cylinder
piston is at the top dead center on the compression stroke.
7. Measure the valve clearance. If the valve clearance is not
as specified, loosen the rocker ann lock nut and adjust the
cleating using a feeler gauge while turning the adjusting
screw.
~''=9
VALVE' CLEARANCE (ENGINE HOT)
INTAKE 0.20mm (0.0079;n)
EXHAUST 0.25mm (0.0098;n)
8. While holding the adjusting screw with a screwdriver
to prevent it from turning, tighten the lock nut to the
specified torque of 15 Nm.
9. Rotate clockwise the cranksh'!fi one complete
turn
(360·)
10. Repeat steps 7 and 8 on the other valves.
11. Install the rocker cover.
12. Install the spark plugs and tighten to 25 Nm.
~
WESTERBEKE
EnglneB & Generators
39