CYLINDER COMPRESSION TEST
Examining the spark plugs and testing cylinder
compression can tell much about the condition of
the
valves, piston rings and cylinders. Test cylinder
compression as follows:
1.
Start the genset and let it warm up.
2. Stop the genset and
remove and inspect the
spark plugs. See IGNITION SYSTEM in this
section.
3. Insert the compression gauge nozzle into one
of the spark plug holes, hold the throttle open
and crank the engine. Note the pressure indi-
cated
by
the gauge.
4.
Repeat the test on the other cylinder.
5.
Refer to Section
9.
Engine Block Assembly if
cylinder compression test pressures do not
meet
Specifications.
CRANKCASE BREATHER ASSEMBLY
See Figure 6-9. The crankcase breather is a reed
valve assembly that opens to discharge crankcase
vapors on the piston down-stroke and closes on the
up-stroke, resulting
in
a negative pressure in the
crankcase when the engine is running. The crank-
case vapors (blowby gases, gasoline vapors, mois-
ture, air) are routed to the carburetor for burning in
the cylinders. A dirty or sticking
valve can cause oil
leaks, high oil consumption, rough idle, reduced en-
gine power and sludge formation within the engine.
Disassembly: The breather assembly is serviced
by disassembling it and cleaning all the parts
in
parts cleaning solvent. The assembly comes apart
when the capscrew is unscrewed.
6-13
14wARNINGI
Most
parts
cleaning
solvents
are
flammable
and
corrosive
and
can cause severe
burns
and
inflammation. Use
only
as
recom-
mended
by
the manufacturer.
Reassembly:
Reassemble using a new gasket.
Replace the reed
valve if it does not lie flat across
the discharge orifice. Torque the
cover capscrew to
12-241bs-in (1.3-2.6 N-m).
14
CAUTION! Over-tightening the
capscrew
can
distort
the
cover
allowing
dirt
to
enter
the en-
gine.
BREATHER
HOSE
FLAT
WASHER
FLAT
WASHER
REED
VALVE
HOSE
CLAMP
/
~
Ill
VALVE
COVER
PACK
GASKET
~~
~#'
-
BREATHER
BAFFLE
FIGURE 6-9. CRANKCASE BREATHER ASSEMBLY
To Next Page
Loading...
Need help?
General
