10
Engine and Engine Parts
We recommend that you see an authorized Briggs &
Stratton Service Dealer for all maintenance and service
of the engine and engine parts. Use only genuine
Briggs & Stratton parts.
This is a single cylinder, L-head, air-cooled engine. It is
a low emissions engine.
In the state of California, the 120000 series engines
covered in this manual are certified by the California Air
Resources Board to meet emissions standards for 125
hours. Such certification does not grant the purchaser,
owner or operator of this engine any additional
warranties with respect to the performance or
operational life of this engine. This engine is warranted
solely according to the product and emissions
warranties stated elsewhere in this manual.
Model Series 120000
Bore
2.69 in. (68.26 mm)
. . . . . . . . . . . . . . . . . . . . . . . . . .
Stroke
2.05 in. (51.99 mm)
. . . . . . . . . . . . . . . . . . . . . . . .
Displacement
11.57 cu. in. (190 cc)
. . . . . . . . . . . . . . . . .
Tune up Specifications
Armature air gap
0.006 -- 0.010 in. (0.15 -- 0.25 mm)
. .
Spark plug gap
0.030 in. (0.76 mm)
. . . . . . . . . . . . . . . . .
Valve clearance with valve springs installed and piston 1/4
in. (6 mm) past top dead center (check when engine is
cold). See Repair Manual P/N 270962.
Intake
0.005 -- 0.007 in. (0.13 -- 0.18 mm)
. . . . . . . . . . . .
Exhaust
0.005 -- 0.007 in. (0.13 -- 0.18 mm)
. . . . . . . . . .
Note:
For practical operation, the horsepower loading should not
exceed 85% of rated horsepower. Engine power will decrease
3-1/2% for each 1,000 feet (300 meters) above sea level and 1%
for each 10
°
F (5.6
°
C) above 77
°
F (25
°
C). It will operate
satisfactorily at an angle up to 15
°
.
Model, Type and Code Number
To get replacement parts or technical assistance in the
future write you engine Model, Type and Code number
along with the date of purchase here. These numbers
are located on your engine. For the location, see page
3,
Engine Features
.
Model Series
Type
Code
If you perform any maintenance on
the engine, first disconnect the spark
plug wire from the spark plug, and
disconnect the battery at the negative
terminal (electric starter engines only)
to prevent unintentional sparking.
Unintentional sparking can result in
fire or electric shock. Unintentional
start-up can result in entanglement,
traumatic amputation or laceration.
Use only correct tools.
•
Do not strike the flywheel with
a hammer or hard object
because the flywheel may
later shatter during operation.
•
Do not tamper with governor
spring, links or other parts to
increase engine speed.
WARNING
The manufacturer of the equipment on which
this engine is installed specifies top speed at
which the engine will be operated. DO NOT
EXCEED this speed.
WARNING
Technical Information
Power Ratings:
The power ratings for an individual
engine model are initially developed by starting with
SAE (Society of Automotive Engineers) code J1940
(Small Engine Power & Torque Rating Procedure)
(Revision 2002-05). Given both the wide array of
products on which our engines are placed, and the
variety of environmental issues applicable to operating
the equipment, it may be that the engine you have
purchased will not develop the rated horsepower when
used in a piece of power equipment (actual “on-site”
power). This difference is due to a variety of factors
including, but not limited to, the following: differences in
altitude, temperature, barometric pressure, humidity,
fuel, engine lubrication, maximum governed engine
speed, individual engine to engine variability, design of
the particular piece of power equipment, the manner in
which the engine is operated, engine run-in to reduce
friction and clean out of combustion chambers,
adjustments to the valves and carburetor, and other
factors. The power ratings may also be adjusted based
on comparisons to other similar engines utilized in
similar applications, and will therefore not necessarily
match the values derived using the foregoing codes.
