Engine Compression Test - Westerbeke SBEG Series Operator's Manual

ENGINE ADJUSTMENTS
NOTE:
WESTERBEKE recommends that the following engine
adjustments be peiformed by a competent engine mechanic.
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 off the raw water intake 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.
COMPRESSION
GAUGE
(TYPICAL)
AOAPTER~r~~~~
~
6. Measure the compression pressure for all the cylinders.
Ensure that compression pressure differential for each
cylinder is within the specified unit.
Compression pressure should nol differ by more than 14 psi (100 Kpa).
7. If a cylinder's compression or pressure differential is
below the lintit, add a small amount of engine oil through
the spark plug hole and repeat steps 4 and 5.
(al If additional of oil causes an increase of pressure, the
piston ring and/or cylinder wall may be worn or damaged.
(b l If additional oil does not increase compression pres-
sure suspect poor valve contact, valve seizure, or valve
wear.
S. Reinstall three plugs and ignition wires.
9. Open the raw water thru seacock.
Engines & Generators
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