Engine Compression
Check compression with engine warm, all spark plugs removed and throttle wide open. Crank engine through at least 6 compression strokes per cylinder to determine engine compression.
CAUTION:
On models with electronic ignition, connect coil high tension wire to ground before cranking engine.
COMPRESSION SPECIFICATIONS
| Application | Specification | ||
|---|---|---|---|
| Compression Ratio | |||
| Air-Cooled | 7.3:1 | ||
| Water-Cooled | 8.6:1 | ||
| Compression Pressure | |||
| Air-Cooled | |||
| Maximum | 145-189 psi (10.0-13.0 kg/cm2 ) | ||
| Minimum | 116 psi (8.0 kg/cm2 ) | ||
| Water-Cooled | |||
| Maximum | 85-135 psi (6.0-9.5 kg/cm2 ) | ||
| Minimum | 71 psi (5.0 kg/cm2 ) | ||
| Max. Variation Between Cylinders | 44 psi (3.0 kg/cm2 ) | ||