| Model Series | Engine Type |
| GX640 | Water-cooled 4-stroke OHV 2-cyl |
| GX100 | 4-stroke OHC |
| GX120 | 4-stroke OHV 1-cyl |
| GX160 | 4-stroke OHV 1-cyl |
| GX200 | 4-stroke OHV 1-cyl |
| GX240K1 | 4-stroke OHV 1-cyl 25deg tilt |
| GX270 | 4-stroke OHV 1-cyl 25deg tilt |
| GX340K1 | 4-stroke OHV 1-cyl 25deg tilt |
| GX390K1 | 4-stroke OHV 1-cyl 25deg tilt |
| GX22 | 4-stroke OHV 1-cyl |
| GX31 | 4-stroke OHV 1-cyl |
| GX610K1 | 4-stroke OHV 90deg V-twin |
| GX620K1 | 4-stroke OHV 90deg V-twin |
| GX670 | 4-stroke OHV 90deg V-twin |
| GXV120 | 4-stroke OHV |
| GXV140 | Single cyl. Vert. OHV |
| GXV160 | 4-stroke OHV |
| GXV270 | 4-stroke OHV 1-cyl |
| GXV340 | 4-stroke OHV 1-cyl |
| GXV610K1 | 4-stroke OHV 90deg V-twin |
| GXV620K1 | 4-stroke OHV 90deg V-twin |
| GX25 | 4-stroke OHC 1-cyl |
| GX35 | 4-stroke OHC 1-cyl |
| GXH50 | 4-stroke OHV 1-cyl |
| GXV50 | 4-stroke OHV 1-cyl |
| GS190 | 4-stroke OHC 1-cyl |
| GSV190 | 4-stroke OHC 1-cyl |
| GC135 | 4-stroke OHC 1-cyl |
| GC160 | 4-stroke OHC 1-cyl |
| GC190 | 4-stroke OHC 1-cyl |
| GCV135 | 4-stroke OHC 1-cyl |
| GCV160 | 4-stroke OHC 1-cyl |
| GCV520 | 4-stroke OHC 90deg V-twin |
| GCV530 | 4-stroke OHC 90deg V-twin |
| GD320 | Forced air-cooled 4stroke overhead 1cyl |
| GD410 | Forced air-cooled 4stroke overhead 1cyl |
| GD1100 | 4-stroke OHC 3-cyl water-cooled |
| GD1250 | 4-stroke OHC 3-cyl water-cooled |
| G150K1 2.6kW | 4-stroke side valve 1 cyl |
| G150K1 2.8kW | 4-stroke side valve 1 cyl |
| G200K1 3.7kW | 4-stroke side valve 1 cyl |
| G200K1 4.0kW | 4-stroke side valve 1 cyl |
| GV100 | 4-stroke side valve 1 cyl |
| GX360 | 4-stroke OHC 2-cyl |