Flywheel | Diameter | Face | Spec Notes | Quantity |
| D174 | 12 inches | Crowned | Spec 10 onwards | One |
| D299 Replaces D174 | 12 inches | Flat | Current flywheel 2hp Hopper or Tank Cooled | One |
| D381 | 18 inches with coupling face | --- | Spec 10 to 13 to engine 101364 | One |
| D373 Replaced by 1/682 | 14 inches | ---- | Spec 13 onwards engine 101365 onwards | One |
| D74 | 12 inches with coupling face | ---- | Spec 10 onwards | One |
| D374 Introduced for steadier running on 700rpm engines | 14 inches | 3¼ | Spec 13 only engine 98000 - 117553 | One |
| D298 Replaced by D1238 | 14 inches | 2¾ | Spec 16 to 26 engine 117554 to 191770 | One |
| D1238 1½hp tank or hopper cooled | 14 inches | 2¾ | Spec 26 onwards engine 191771 to date | One |
| F174 Replaced by F176 (12") With cast in pulley for flat fan belt | Not stated | ---- | Spec 10 to 18 engine 80000 to 127692 | One |
| F176 Replaces by F174 With coupling faces | 12 inches | ---- | Spec 18 onwards engine 127693 onwards | One |
| D372 Replaced by 1/682 With cast in pulley for flat fan belt | 14 inches | ---- | Spec 10 to 18 engine 80000 to 127692 | One |
| 1/682 Replaces D372 With coupling faces | 14 inches | ---- | Spec 18 onwards engine 127693 | One |
| D684 Radiator cooling with flat belt coupling | 14 inches | ---- | Not stated | One |