Yanmar Engine - S Series
Vertical models, updated two times with the SVE engines followed by the SB. Single cylinder, 2:1 or 3:1 transmissions, sea water cooled, heavy duty. This series includes the following engines:
| Engine | HP | Years In Production | Comments |
| SB12 | 12 | 1976 - 1980 | B=Between |
| SB8 | 8 | 1976 - 1980 | B=Between |
| SVE12 | 12 | 1974 - 1976 | E=Early |
| SVE8 | 8 | 1974 - 1976 | E=Early |