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Sears ST 12 Technical Specifications

General Information

Tractor Model ...................... Sears ST12 917.2573
Tractor Type ...................... Garden tractor
Manufacture Years ...................... 1973-1974
Fuel Type ...................... Gasoline
Attachments ...................... Mower Deck, Blade and Snowblower

Sears ST 12 Engine

Engine Model ...................... Tecumseh HH120
Engine Type ...................... 4-cycle air-cooled single cylinder gasoline
Number of Cylinders ...................... 1
Displacement, cu.in (cc) ...................... 27.7 (453)
Engine Bore, in (mm) ...................... 3.50 (89.0)
Engine Stroke, in (mm) ...................... 2.88 (73.0)
Maximum Engine Power, hp (kW) ...................... 12.0 (8.9)
Rated Engine Speed, rpm ...................... 3600
Idle Speed, rpm ...................... 1600
Fuel System ...................... Carburetor
Carburetor Type ...................... Float-feed
Fuel Pump ...................... Impulse type
Governor ...................... Centrifugal flyball type
Lubrication System ...................... Splash type
Air Cleaner ...................... Dry element
Ignition System ...................... Flywheel magneto
Spark Plug Gap, in (mm) ...................... 0.028-0.033 (0.711-0.838)
Intake Valve Clearance, in (mm) ...................... 0.010 (0.25)
Exhaust Valve Clearance, in (mm) ...................... 0.020 (0.51)
Fuel Tank Capacity, gal (L) ...................... 1.8 (6.5)
Oil Capacity, qts (L) ...................... 1.6 (1.5)

Electrical System

Electrical System Rating, Volts ...................... 12
Starter Type ...................... Electric
Number of Batteries ...................... 1
Electric Ground ...................... Negative

Power Take Off

PTO Operational Type ...................... Independent
PTO Clutch ...................... Mechanical
PTO Speed, rpm ...................... 3000

Sears ST 12 Transmission

Transmission Type ...................... Belt-driven gear
Gearbox Type ...................... 6F/2R
Number of Forward Gears ...................... 6
Number of Reverse Gears ...................... 2
Maximum Forward Speed, mph (kph) ...................... 6.5 (10.5)
Maximum Reverse Speed, mph (kph) ...................... 2.5 (4.0)

Wheels and Tires

Drive Wheels ...................... 2WD 4x2
Steering Configuration ...................... Front steer
Steering System ...................... Manual
Front Tire Size ...................... 16x5.50x8
Rear Tire Size ...................... 22.5x7.50x12

Dimensions and Weight

Wheelbase, in (mm) ...................... 43.5 (1100)
Length, in (mm) ...................... 68.5 (1730)
Height, in (mm) ...................... 44 (1110)
Overall Width, in (mm) ...................... 36.5 (925)
Weight, lb (kg) ...................... 641 (290)

Sears ST 12 Attachments

42" Mower Deck

Mower Deck Type ...................... Mid-mount, right-discharge
Number of Blades ...................... 3
Cutting Width, in (mm) ...................... 42 (1060)
Cutting Height, in (mm) ...................... 1.5-4.5 (38-114)
Deck Drive ...................... Belt
Lift System ...................... Mechanical
Weight, lb (kg) ...................... 169 (76)

48" Mower Deck

Mower Deck Type ...................... Mid-mount, right-discharge
Number of Blades ...................... 3
Cutting Width, in (mm) ...................... 48 (1215)
Cutting Height, in (mm) ...................... 1.5-4.5 (38-114)
Deck Drive ...................... Belt
Lift System ...................... Mechanical
Weight, lb (kg) ...................... 182 (82)

39" Snow Blower

Snowblower Type ...................... Front-mount
Clearing Width, in (mm) ...................... 39 (990)
Lift System ...................... Mechanical
Weight, lb (kg) ...................... 177 (80)

Front Blade

Blade Type ...................... Front-mount
Width, in (mm) ...................... 46 (1160)
Height, in (mm) ...................... 17 (430)
Lift System ...................... Mechanical
Angle ...................... Manual