The Gravely 8121 is a lawn tractor with a power output of approximately 12 hp, a typical figure for its class. It was manufactured in 1978. Powered by a 1-cylinder petrol air-cooled engine, the tractor features two-wheel drive with an 8-speed gearbox. Its operating weight is listed as 403 kg, suitable for operations covering up to 200 acres.
Provisional listing — the headline figure is shown; full specifications are auto-generated and pending verification against published sources.
Rated power
12 hp
Weight
403 kg
Catalogue coverage
Variants represented
2
Richest spec table
47 rows
Recorded power
12 hp
Recorded weight
403 kg
Transmissions
8-speed gear
Production years
1978-1978
Verified variants
0
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Overview
ManufacturerGravelyReference
Garden tractorReference
Two-wheel driveReference
Manual steeringReference
Mechanical band brakesReference
Open operator station.Reference
Variants
8120mechanical liftReference
8121hydraulic liftReference
Engine
12HP Kohler 476cc 1-cyl gasolineReference
Kohler K301Reference
gasolineReference
1-cylinderReference
air-cooled horizontal-shaftReference
Displacement29.07 ciReference
Bore/Stroke83 x 86 mmReference
Power (gross)8.9 kWReference
StarterelectricReference
Starter volts12Reference
Oil capacity1.9 LReference
Transmission
8-speed gearReference
Typeshaft-driven gearReference
Gears8 forward and 4 reverseReference
Four gears (1-4) in two ranges (low/high) with directional control lever (forward/reverse). Reverse speeds are the same in high or low range.Reference
Capacities
Fuel20.1 LReference
PTO & Hydraulics
Hydraulic system1.4 LReference
Typeopen centerReference
Capacity1.4 LReference
Pressure82.7 barReference
Pump flow6.4 lpmReference
Mid PTOindependentReference
ClutchmechanicalReference
Dimensions
Wheelbase121 cmReference
Weight403 kgReference
Front tire16x7.50-8Reference
Rear tire23x10.50-12Reference
Lawn/turf front16x7.50-8Reference
Lawn/turf rear23x10.50-12Reference
Length191 cmReference
Width92 cmReference
Height109 cmReference
Shipping weight403 kgReference
Ground clearance17 cmReference
Electrical
GroundnegativeReference
Charging systemflywheel alternatorReference
Charging amps15Reference
Battery volts12Reference
Battery AH42Reference
Values normalized to UK metric units. Every figure is traced to at least one source; verified specs are cross-checked against two or more.
