Simplicity Sovereign 18H garden tractor specs and service data

The Simplicity Sovereign 18H is a garden tractor model from the Sovereign series, manufactured from 1993 to 2000 by Simplicity in Port Washington, Wisconsin, USA. It was available in two-wheel drive (2WD) version.

The Simplicity Sovereign 18H is equipped with a 624 cc (38.1 cu·in) two-cylinder gasoline engine with 77.0 mm (3.03 in) of the cylinder bore and 67.0 mm (2.64 in) of the piston stroke, and a belt-driven hydrostatic transmission with infinite forward and reverse gears.

The Simplicity Sovereign 18H garden tractor features:

The Kohler CH18 gasoline engine which produces 18.2 PS (13.4 kW; 18.0 HP) at 3,600 rpm of horsepower
Manual or power (optional) steering
Mechanical band brakes
Open operator station
Sleeve hitch (optional)
Independent middle PTO with manual clutch
11.4 liters (3.0 US gal.; 2.5 Imp. gal)

General specifications

General Specifications
Model	Simplicity Sovereign 18H
Tractor type	Garden tractor
Production years	1993-2000
Factory	Port Washington, Wisconsin, USA
Dimensions and weight
Length	1,770 mm (69.7 in)
Width	930 mm (36.6 in)
Height (steering wheel)	1,000 mm (39.4 in)
Wheel base	1,280 mm (50.4 in)
Weight	312 kg (688 lbs)
Fuel capacity
Fuel tank capacity	11.4 liters (3 US gal.; 2.5 Imp. gal)

Engine

Engine
Engine model	Kohler Command PRO CH18S
Engine type	4-stroke, OHV, V-twin
Displacement	624 cm ³ (38.0 cu-in)
Compression ratio:	8.5:1
Cylinder bore:	77.0 mm (3.03 in)
Piston stroke:	67.0 mm (2.64 in)
Max. horsepower	18.2 PS (13.4 KW; 18.0 HP) at 3,600 rpm
Max. torque	43.6 Nm (4.45 kg·m; 32.2 ft·lb) at 2,200 rpm
Cooling system	Forced air
Air cleaner	Replaceable, paper element
Lubricating system	Full pressure
Ignition system	Electronic ignition
Fuel system	Carburetor with fixed main jet
Fuel used	Unleaded gasoline (octane number 86 or higher)
Starting system	Electric starter
Governor	Mechanical centrifugal governor
PTO shaft rotation	Counterclockwise (from PTO shaft side)
Dimensions (L x W X H)	355 x 451 x 483 mm (14.0 x 17.7 x 19.0 in)
Dry weight	41.0 kg (90.0 lbs)
Compression pressure
Standard:	1.1 MPa (160 psi)
Compression differential limit between cylinders:	15% and less
Oil system
Oil type:	API SG, SH, SJ, or higher
Recommended oil:	SAE 10W-30
Oil capacity:	W/o oil filter: 1.7 L (1.8 US. qt, 1.5 Imp. qt.) With oil filter: 1.9 L (2.0 US.qts, 1.7 Imp. qts)
Fuel system
Fuel pump:	Pulse type
Fuel filter:	In-line
Ignition system
Spark plug:	Champion RC12YC
Spark plug gap:	0.76 mm (0.030 in)
Ignition coil air gap	0.280-0.330 mm (0.011-0.013 in)

Transmission and chassis

Chassis, steering and brakes
Chassis	2WD
Steering type	Manual or power (optional)
Brakes	Mechanical band brakes
Transmission
Transmission manufacturer or model	–
Transmission type	Belt-driven hydrostatic
Gears	Infinite forward and reverse
Speed	Forward: 11.3 kmh (7.0 mph) Reverse: 6.4 kmh (4.0 mph)

Tires

Tires
Front tires	Lawn/turf: 16×6.50-8
Rear tires	Lawn/turf: 23×10.5-12

Rear Hitch

Three-Point Hitch
Category	Sleeve hitch (optional)
Control type	–
Lift capacity (at ends)	–

PTO (Power take-off shaft)

PTO
Middle PTO type	Independent with manual clutch
Middle PTO speed	–

Electrical system

Electrical system
Ground	Negative
Charging system	–
Charging amps	–
Battery	12V

Attachments

Simplicity 1691218: 42″ mid-mount mower deck with 3-blade
Cutting width	1,060 mm (42.0 in)
Total width	1,420 mm (56.0 in)
Cut height	30-70 mm (1.5-3.1 in)
Weight	57 kg (127 lbs)
Simplicity 1691219: 48″ mid-mount mower deck with 3-blade
Cutting width	1,210 mm (48.0 in)
Total width	1,570 mm (62.0 in)
Cut height	30-70 mm (1.5-3.1 in)
Weight	59 kg (153 lbs)
Simplicity 1691520: 42″ front-mount blade
Cutting width	1,060 mm (42.0 in)
Weight	31 kg (70 lbs)
Simplicity 1691521: 36″ front-mount snowblower
Cleaning width	910 mm (36.0 in)
Weight	59 kg (131 lbs)
Simplicity 1691522: 42″ front-mount snowblower
Cleaning width	1,060 mm (42.0 in)
Weight	64 kg (143 lbs)

Author: Sergei Wers
About: Co-founder and CEO of a multi-brand auto repair shop (engine repair, chassis repair, body repair and painting) for over 15 years. I have been developing internet sites with technical specifications for more than seven years.

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We try to use official documentation and verify the published data, but errors may occur. In addition, specifications of machinery and equipment may vary depending on markets and modifications. We do not recommend the use of this data for spare parts or repairs. Use official service manuals or parts catalogs for your product.

Simplicity Sovereign 18H