The Tecumseh HH100 is a 389 cc (23.7 cu·in) single-cylinder air-cooled four-stroke internal combustion gasoline engine, manufactured by Tecumseh.
The Tecumseh HH100 engine has an L-head (side valve) design, horizontal PTO shaft, cast-iron cylinder block, and cast-iron cylinder head. This engine can be equipped with Tecumseh or Walbro carburetor and solid-state ignition system (CDI).
The cylinder bore is 84.1 mm (3.31 in) and the piston stroke is 69.8 mm (2.75 in). Compression ratio rating is 6.70:1. This engine produced 10.2 PS (7.5 kW; 10.0 HP) of horsepower.
The breakdown of the engine code is as follows:
- HH – Horizontal-Heavy Duty
- 100 – 10.0 HP
General information
| 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) |
| Fuel tank capacity | – |
Cylinder Block and Head
| 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 (3.308-3.310 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) | |
| 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) | |
Tightening torque specs
| 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 |
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 |
best help I have found.
Do have a pin and seat kit for LME 29 Walbro Carburetor .
And an after market carburetor.
For Sears 10xl 1971 riding mower.
A Service Main Nozzle, under cut.
Fixed High speed nut and pin
Float damper spring