Engine Compression Test; Water Pump Belt; Ignition Timing - Westerbeke 3.0 BPMG Operator's Manual

ENGINE ADJUSTMENTS
ENGINE COMPRESSION TEST
To check the engine's compression pressure, warm up the
engine, then shut it down.
1. Remove both spark plug caps and both spark plugs.
2. Install
a
compression adapter and gauge in a spark
plug hole.
3. Close the tlu·u hull valve (seacock).
4. Crank the engine several times quickly so ~hat the gauge
pointer reaches it's maximum.
STANDARD COMPRESSION PRESSURE AT 500 RPM:
71 psi, (5 .1 kgf/CM ) ,(0.50 MPa) with decompressor
186 psi, (13.8 kgf/cm ), (l.35 MPa) without decompressor
5. Test the compression pressure on the other cylinder.
If either cylinder is below the standard tTy adding a
small amount of engine oil tlu·ough the spark plug hole
and repeat the test.
(a) If additional oil causes an increase of pressl.Jre,
the piston ring and/or cylinder
nmy
be worn
or
damaged.
(b) If additional oil does not increase compression
pressure suspect poor valve contact, valve seizure
or valve
wear.
6.
Reinstall the two plugs, connect the
wires
and open the·
thru hull valve (seacock).
IGNITION TIMING
The magneto employs the electric ignition advance system
that advances ignition timing with an increase of engine
speed. While mnning the engine, check the ignition tinting
with a timing light.
There are nine (9) markings (fDC, ATDC 5° and BTDC 5°,
10°, 15°, 20°, 25°, 30i
0
,
35) on the flywheel cup.
Check the timing while observing the position of the carved
marking on the starter case.
WATER PUMP BELT
To remove, replace or aojust the belt, loosen the pivot bolt
and release the adjusting bolt. Slide the water pump bracket
to slacken the belt for removal. When replacing and
adjusting the belt, set tl1e belt very tight and tighten the bolt
and nut
The dual water pumps on the
FRESH WATER COOLED
. MODELS
use the saine drive belt and the adjustment
is the
Bame.
'...
'·,
WATER PUMP BRACKET
'V'"
' ' I I-,,.:;....
'/;'~;
==-=M--<
-·-·--=~
I~
@:
NOTE:
The
a.djus~~ient
is the same for the FRESH WATER
COOLED MODEL dual pumps.
BTDC
IGNITION TIMING
IN DEGREES
30
·25-1----+~.::;;....
_ _ _ ,
20
10
5
0
""--"'---1+-,f-_..___..___.____,
I
. 1
FLYWHEEL
0 3 4 5 6
x
103
Engine speed rpm
Engines
&
Generators
26