O and R ENGINES (FORMERLY OHLSSON AND RICE)
(SOURCE: Some of the data is from “Small Engines Service Manual”)
Listed below are the various models of the O and R engines and some data regarding them.
| Model | Governor | Bore | Stroke | Displacement | Carburetor | Spark Plug Diameter | Spark Plug Gap |
|---|---|---|---|---|---|---|---|
| Compact I | Air-Vane | 1.250 | 1.032 | 1.26 | Diaphragm Type | *10 mm or 14 mm | 0.025 or 0.030 |
| Compact II | Air-Vane | 1.250 | 1.096 | 1.34 | Diaphragm Type | 10 mm or 14 mm | 0.025 or 0.030 |
| Compact III | Air-Vane | 1.250 | 1.096 | 1.34 | Diaphragm Type | 10 mm or 14 mm | 0.025 or 0.030 |
| Compact I3A | Air-Vane | 1.250 | 1.096 | 1.34 | Diaphragm Type | 10 mm or 14 mm | 0.025 or 0.030 |
| 20A | Air-Vane | 1.437 | 1.250 | 2.0 | Walbro HDC | **CJ6 or CJ4 | 0.025 |
SPARK PLUG DATA:
* Model using 10 mm spark plug, recommended plug is Champion UY-6 or equivalent.
* Model using 14 mm spark plug, recommended plug is Champion CJ-8 or equivalent for heavy duty use and Champion CJ14 or equivalent for light use.
** Reccommended plug is Champion CJ6 for normal use and CJ4 plug for heavy use.
