Briggs & Stratton Twin Cylinder L-Head Repair Manual page 15

1
Clean Cooling System
Grass particles, chaff or dirt can clog the air cooling
system, especially after prolonged service in cutting
dry grass or very dirty air. Continued operation with a
clogged cooling system can cause severe overheating
and possible engine damage. Fig. 4 shows the blower
housing removed and areas to be cleaned. This should
be a regular maintenance operation, performed yearly
or every 100 hours, whichever comes first.
Replace Spark Plugs
Replace spark plugs every 100 hours of operation or
every season, whichever occurs first. Replace spark
plugs if electrodes are burned away, or the porcelain is
cracked. Set spark plug gap at .030" (.76 mm) for all
models, Fig. 5.
.030" (.76 mm)
WIRE GAUGE
Fig. 5 – Adjusting Spark Plug Gap
NOTE: Do not blast clean spark plugs. Spark
plugs should be cleaned by scraping or
hand wire brushing and washing in a
commercial solvent.
The spark plugs recommended for Briggs & Stratton
twin cylinder engines are as follows:
Spark Plug
Champion
Type
Standard Plug J-19 LM
Resistor Plug RJ-19 LM
Resistor Plug
6
Fig. 4
B&S Part No.
492167
802592
RJ-12 394539
Air Cleaner Maintenance
WARNING: NEVER OPERATE engine with
air cleaner cover or air cleaner element
removed! Fire may result.
A properly serviced air cleaner protects internal parts
of the engine from dirt and dust particles in the air. If air
cleaner instructions are not carefully followed, dirt and
dust which should be collected in the cleaner, will be
drawn into the engine. These particles are highly
abrasive and will cause the piston rings and cylinder
bore to wear quickly. As the rings and cylinder bore
become worn, these abrasive particles enter the
crankcase and contaminate the oil, forming an abra-
sive mixture which will cause wear on all of the internal
moving parts.
The air cleaner on every engine brought in for a check up
or repair should be examined and serviced. If the air
cleaner shows signs of neglect or damage, show it to the
customer. Instruct the customer on proper care, to
ensure long engine life.
NOTE: Replace air cleaner gaskets and mounting
gaskets that are worn or damaged, to
prevent dirt and dust entering engine due
to improper sealing. Replace bent air
cleaner mounting bracket.
Service Dual Element Air Cleaner
Service/replace foam pre-cleaner at three month inter-
vals or every 25 hours, whichever occurs first, Fig. 6 or
Fig. 7. Replace cartridge every 100 hours or every
season, whichever occurs first.
NOTE: Service/replace air cleaner more often
under dusty conditions.
To Service Pre-Cleaner
1. Remove knob(s) and cover.
2. Remove foam pre-cleaner by sliding it off the pa-
per cartridge.
3. Wash foam pre-cleaner in liquid detergent and
warm water.
a. Wrap foam pre-cleaner in cloth and squeeze
dry.
b. Saturate foam pre-cleaner in engine oil.
Squeeze to remove excess oil.
4. Install foam pre-cleaner over paper cartridge.
Reassemble cover and screw knob(s) down tightly.
NOTE: Replace cup washer if damaged, Fig. 6 or
Fig. 7.
To Service Cartridge
1. Remove knob(s) and cover, Fig. 6 or Fig. 7.
a. Remove and inspect cartridge. Replace if
damaged or dirty.