The Onan P218G (Performer 18) is a 782 cc (47.7 cu-in) two-cylinder air-cooled four-stroke internal combustion small gasoline engine with a horizontal shaft manufactured by Onan for general-purpose applications.
The P218G engine has an L-head design with two flat cylinders, an aluminum cylinder block, a carburetor fuel system, an electronic battery ignition system, and an electric starter.
The cylinder bore is 82.55 mm (3.25 in) and the piston stroke is 73.01 mm (2.87 in), the compression ratio rating is 7.0:1. The Onan P218G engine produced 18.2 PS (13.4 kW; 18.0 HP) at 3,600 rpm of horsepower.
The breakdown of the engine code is as follows:
- P – Engine Family
- 2 – Two cylinder
- 18 – 18.0 BHP power
- G – Gasoline
General information
Engine Specifications | |
Model | Onan P218G (Performer 18) |
Type | 4-stroke, L-head, flat |
Displacement | 782 cm3 (47.7 cu-in) |
Max. horsepower | 18.2 PS (13.4 kW; 18.0 HP) at 3,600 rpm |
Max. torque | – |
Fuel system | Carburetor with fixed main jet |
Cooling system | Forced-air |
Ignition system | Electronic battery ignition system ignition system |
Lubricating system | Forced lubrication |
Starting system | Electric starter |
PTO shaft rotation | Clockwise (viewed from flywheel) |
Cylinder Block and Head
Cylinder block | ||
Compression ratio: | 7.0:1 | |
Bore x Stroke | 82.55 X 73.00 mm (3.25 x 2.87 in) | |
Sleeve internal diameter | 82.530-82.550 mm (3.2492-3.25 in) | |
Piston skirt outer diameter | 82.420-82.440 mm (3.2449-3.2457 in) | |
Ring end gap | Top/Second | 0.076-0.203 mm (0.003-0.008 in) |
Connecting rod small end ID | 17.470-17.480 mm (0.6878-0.6882 in) | |
Piston pin outer diameter | 17.463-17.468 mm (0.6875-0.6877 in) | |
Crankpin diameter | 41.280-41.300 mm (1.6252-1.626 in) | |
Crankshaft main journal diameter | 50.780-50.800 mm (1.9992-2 in) | |
Cylinder Head | ||
Valve Arrangement: | L-haed, gear driven | |
Valves: | 4 (2 per cylinder) | |
Stem outer diameter (standard): | INTAKE | 7.099-7.112 mm (0.2795-0.2800 in) |
EXHAUST | 7.061-7.074 mm (0.2780-0.2785 in) | |
Valve spring free length: | 40.640 mm (1.6 in) | |
Lobe height: | INTAKE | 28.880 mm (1.1370 in) |
EXHAUST | 29.390 mm (1.1571 in) |
Service Information
Engine | |
Maximum speed | 3,600 |
Cylinder compression | 517-793 kPa (75 to 115 psi) |
Valve clearance | |
Intake valve clearance | 0.130 mm (0.0051 in) |
Exhaust valve clearance | 0.330 mm (0.0130 in) |
Oil system | |
Oil type: | API SF, SF/CC, or SF/CD |
Recommended oil: | SAE 5W-30, 10W-30, 30W, 40W |
Oil capacity |
Without oil filter: Standard base: 1.4 L (1.5 US. qt, 1.2 Imp. qt.) High capacity base: 2.6 L (2.75 US. qt, 2.3 Imp. qt.) Oil filter: 0.3 L (0.32 US. qt, 0.26 Imp. qt.) |
Ignition system | |
Ignition timing | 20° B.T.D.C. |
Spark plug | NGK BPR5EFS, Champion RS14YC |
Spark plug gap | 0.640 mm (0.0252 in) |
We try to use verified sources and official documentation, however, differences between sources or errors in entering information may occur. We do not provide advice on technical issues related to the engines operation or repair. We do not recommend using provided information for engines repairing engines or spare parts ordering, use only official service manuals and spare-parts catalogs.
great info source . thank you