Gravely lawn tractors

Gravely Pro Master 20-H

The Gravely Pro Master 20-H is a front-mount mower lawn tractor produced from 1989 to 1991 by Gravely, a part of Ariens. It features a 20 horsepower engine option from either Kohler or Onan, hydrostatic Eaton 850 transmission with infinite forward and reverse speeds, and an open operator station. It has a 5.3 gallon fuel tank and weighs 980 lbs with the 60-inch mower attached. The tractor uses 18x8.50-8 front tires and 4.80/4.00-8 rear tires. It offers front PTO with an independent electric clutch. Attachments include 50-inch and 60-inch front-mount mower decks with hydraulic lift and right discharge.

Power-

Founded-

ModelPro Master 20-H

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Technical Specifications

Detailed specifications and technical data for Gravely Pro Master 20-H

Engine

Onan	gasoline, 2-cylinder, air-cooled
Starter	electric
Fuel tank	5.3 gal (20.1 L)
Kohler M20	gasoline, 2-cylinder, air-cooled horizontal-shaft horizontally-opposed
Power Onan	20 hp (14.9 kW)
Bore/Stroke	3.12x3.06 inches (79 x 78 mm)
Displacement	770 cc (46.98 ci)
Oil capacity	2 qts (1.9 L)
Power (gross)	20 hp (14.9 kW)
Starter volts	12
Engine options	20HP Kohler 770cc 2-cyl gasoline; 20HP Onan 781cc 2-cyl gasoline
Bore/Stroke Onan	3.258x2.875 inches (83 x 73 mm)
Displacement Onan	781 cc (47.7 ci)

Dimensions

Height	48 inches (121 cm)
Length	105 inches (266 cm)
Weight	980 lbs (444 kg) *Weight with 60-inch mower
Rear tire	4.80/4.00-8
Front tire	18x8.50-8

Electrical

Ground	negative
Battery volts	12
Charging amps	15 (Kohler), 20 (Onan)

Production

Type	Front-mount mower
Years made	1989 - 1991

Attachments

50" front-mount mower deck	Lifthydraulic lift Mountfront-mount Width50 inches (127 cm) Blades3-blade Weight215 lbs (97 kg) Dischargeright-discharge Cut height1 to 4 inch (2 to 10 cm) ManufacturerGravely
60" front-mount mower deck	Lifthydraulic lift Mountfront-mount Width60 inches (152 cm) Blades3-blade Weight297 lbs (134 kg) Dischargeright-discharge Cut height1 to 4 inch (2 to 10 cm) ManufacturerGravely