Lawn-Boy M Series User Manual

MOWER SPECIFICATIONS
M21ZPR
M25,5 H.P. commer-
cial grade, 2 cycle
engine. Cast iron
cylinder sleeve, large
diameter forged
steel
crankshaft, forged
steel connecting rod,
upper and lower ball
bearings, mechanical
governor, paper air
filter with pre cleaner.
MODEL
ENGINE
M21 ZMR
M25,5 H.P. commer-
cial grade, 2 CYCLE
engine. Cast iron
cylinder
sleeve, large
diameter forged steel
crankshaft, forged
steel connecting rod.
upper and lower
ball
bearings, mechanical
governor, paper air
filter with pre cleaner.
MOWER TYPE
Rear Bagger dedicated
Rear Bagger dedicated
MOWER DECK
Magnesium,
21' cut, 7
cut heights 1'- 3 1/2'
Magnesium, 21' cut, 7
cut heights 1' 3 1/2'
Three speed gear
drive
DRIVE Push
STARTER
Top mount
Top mount
COMPLIANCE
SYSTEM
Zone
Zone
FUEL CAPACITY
1.6 quart
1.6 quart 1.6 quart
HANDLES
3-position. adjustable,
extruded aluminum
3-position adjustable, 3-position, adjustable,
extruded aluminum extruded aluminum
8' Front and Rear,
radial tread
8' Front and Rear,
radial tread
Standard, rear Standard, rear
%position, adjustable,
extruded aluminum
B' Front and Rear,
radial tread
WHEELS
B' Front and Rear,
radial tread
CATCHER standard, rear
standard, rear
ENGINE SPECIFICATIONS
Horse Power 5 HP @ 3600 RPM
PISTON RINGS
Thickness Top Ring .06081.0592
Thickness Bottom Ring .0625/.0615
End Gap (In Cylinder) Top Ring .0071.021
End Gap (In Cylinder) Bottom Ring .0071.021
Bore
Stroke
Displacement Cu. In.
Displacement CC's
Compression Ratio
Compression (normal) Cold
Hot
Compression (minimum)
Cold
Governor Speed High
Governor Speed Low
Fuel/Oil Ratio
2.380
2.00
8.84
145
6.96:l
115-135 psi
110-130 psi
90 psi
3100-3300 RPM
2100-2300 RPM
64:1
CYLlNDER
Diameter (Inside)
2.381/2.380
CRANKCASE
Diameter Top Main Bearing 2.0469/2.0462
Through Bore In
Diameter Lower Main Both Ends
of
Bearing Cylinder-Crankcase
Assembly
CRANKSHAFT
Bearing Journals Top and Bottom
Crank Pin
Wrist Pin diameter
.98401.9835
.7874/.7870
.5630/.5628
FLYWHEEL AIR GAP
C.D. Module Air Gap
Alternator Air Gap
SPARK PLUGGAP
Type Spark Plug: Champion
Canada: Champion
Spark Plug Gap
.010
.010
PlSTON
Diameter (Right Angle
Wrist Pin Hole-Bottom
of Skirt)
Diameter (Parallel with Wrist Pin
Hole Bottom of Skirt)
Diameter Wrist Pin Hole
2.3792/2.3782
CJ-14
QJ-12
.035
2.3752/2.3742
.5635/.5631
1-4

Lawn-Boy M Series Specifications

General

Brand	Lawn-Boy
Model	M Series
Category	Lawn Mower
Language	English