Crankcase Breather; Spark Plugs; Clean Spark Arrester Screen; Remove Combustion Deposits - Lincoln Electric RANGER 9 SVM 110-A Service Manual

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CRANKCASE BREATHER: The Onan engine is
equipped with a crankcase breather that prevents
pressure from building up inside the crankcase, pre-
vents moisture contamination from moisture, gasoline
vapors, or combustion vapors. If the breather valve
becomes sticky, it can cause oil leaks, oil consump-
tion, rough idle, reduced power, and sludge and var-
nish buildup in the engine.
The breather cannot be serviced. However, it should
be periodically inspected and replaced if cracked or
broken, or if the crankcase becomes pressurized.
Evidence of high pressure includes oil leaks at the
seals or excessive oil in the air cleaner housing.
CLEAN ENGINE: Remove dirt and debris with a cloth
or brush. Do not clean with a forceful spray of water.
Water might contaminate the fuel system.
CAUTION
Periodically clean the muffler area to remove com-
bustible debris.
CLEAN AIR INTAKE/COOLING AREAS: To ensure
proper cooling, make sure the grass screen, cooling
fins, and other external engine surfaces are always
kept clean. This will prevent overspeeding, overheat-
ing, and engine damage due to dirt or debris buildup.
Every 50 operating hours or as often as necessary,
remove the blower housing and other cooling shrouds.
Clean the cooling fins and external surfaces as neces-
sary. Make sure to replace all the cooling shrouds.
Running the engine without the cooling shrouds will
cause damage to the engine from overheating.
CLEAN OR REPLACE SPARK PLUGS: Clean or
replace the spark plugs after every 500 hours of oper-
ation as follows.
1. Before removing the plugs, clean the base area to
keep dirt from falling into the engine through the
plug hole.
2. Remove and inspect the plugs.
signs of fouling or electrode wear should be
replaced. Do not blast the spark plugs clean with
an abrasive cleaning device. Clean the plugs by
scraping or by using a wire brush. Wash the plugs
with a commercial solvent.
3. After cleaning or when installing a new spark plug,
set the terminal gap with a feeler gauge.
Figure D.3.
RANGER 9
MAINTENANCE
Gap Specifications: 0.025 inch (.64 mm)
CLEAN SPARK ARRESTER SCREEN: If the muffler
has the optional spark arrester, remove it every 50
hours or once a year, whichever comes first, and
inspect it. Clean the arrester. Replace it if you find any
damage.
REMOVE COMBUSTION DEPOSITS: Combustion
deposits (carbon) can form on the cylinder, cylinder
head, top of the piston, and around the valves over
time, depending on engine loading conditions, type of
fuel used, and other factors that affect engine perfor-
mance. Consult your local Onan engine distributor for
recommended cleaning intervals and procedures.
Plugs showing
See
FIGURE D.3 - SET SPARK PLUG GAP
Spark Plug Wire Gauge
Ground
Electrode
Gap: 0.025 inch (.64 mm)
Gap: Onan - 0.025 inch (.64 mm)
Kohler - 0.040 inch (1.02 mm)
D-5
RANGER 9