Tecumseh HH100 (10 HP, 389 cc) Engine Specs & Review

Tecumseh HH100 Engine Specs

The Tecumseh HH100 engine is a 23.7 cu·in (389 cc) single-cylinder air-cooled four-stroke internal combustion gasoline engine made by Tecumseh. 

This Tecumseh HH100 engine produced 10.2 PS (7.5 kW; 10.0 HP) horsepower. The Tecumseh HH100 engine cylinder bore is 84.1 mm (3.31 in), and the piston stroke is 69.8 mm (2.75 in). 

This Tecumseh HH100 engine can be fitted with Tecumseh or Walbro carburetor and solid-state ignition system (CDI). 

The Tecumseh HH100 engine has a horizontal PTO shaft, cast-iron cylinder block, an L-head (side valve) design, and cast-iron cylinder head. 

The breakdown of the Tecumseh HH100 engine code is as follows:

  • HH – Horizontal-Heavy Duty
  • 100 – 10.0 HP

Tecumseh HH100 Engine Specs

Tecumseh HH100 (10 HP, 389 cc) Engine Specs

Engine Specifications

Model HH100
Type 4-stroke, L-head, single cylinder
Displacement 389 cm3 (23.7 cu-in)
Max. horsepower 10.2 PS (7.5 kW; 10.0 HP)
Max. torque (crank PTO)
Fuel system Carburetor (Tecumseh or Walbro)
Cooling system Forced-air
Ignition system Solid-state ignition system (CDI)
Lubricating system Splash type
Starting system Recoil or electric starter
Fuel used Unleaded gasoline (octane number 86 or higher)

Tightening torque specs

Cylinder head bolt 20.3-27.1 Nm; 2.07-2.76 kg·m; 15-20 ft·lb
Flywheel nut 67.8-74.6 Nm; 6.9-7.6 kg·m; 50-55 ft·lb
Spark plug 25-30 Nm; 2.55-3.06 kg·m; 18-22 ft·lb

Cylinder Head

Valve Arrangement: L-head (sidevalve)
Valves: 2
Valve spring free length: 47.879 mm (1.885 in)
Camshaft lobe diameter: 33.134-33.236 mm (1.3045-1.3085 in)

Cylinder block

Bore x Stroke 84.1 X 69.8 mm (3.31 x 2.75 in)
Sleeve internal diameter 84.125-84.150 mm (3.312-3.313 in)
Piston skirt outer diameter 84.023-84.074 mm (3.308-3.31 in)
Number of piston rings (compression / oil): 2 / 1
Ring end gap Top 0.178-0.508 mm (0.007-0.02 in)
Second 0.178-0.508 mm (0.007-0.02 in)
Piston pin outer diameter 17.457-17.463 mm (0.6873-0.6875 in)

Service Information

Valve clearance
Intake valve clearance 0.254 mm (0.010 in)
Exhaust valve clearance 0.508 mm (0.020 in)
Oil system
Oil type API SF, SJ
Recommended oil SAE 30, 10-W30
Oil capacity 1.4 liters (1.5 US.qts, 1.23 Imp. qts)
Ignition system
Spark plug Champion J-8
Spark plug gap 0.763 mm (0.03 in)
Fuel system
Type Carburetor (Tecumseh or Walbro)
Main adjustment screw Tecumseh: 1-3/4 turns
Walbro: 1-1/2 turns off seat
Idle adjustment screw Tecumseh: 1-1/4 turns
Walbro: 1-1/4 turns off seat

Also Check:

Final Words

This concludes our discussion of the Tecumseh HH100 (10 HP, 389 cc) Engine specs and review; however, if you have any questions regarding this article, please submit them in the comment section below. We will do our best to respond to you as soon as possible.

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