Yanmar Engine - GM/HM Bored Up Series
Similar to the earlier standard GM/HM series, these engines provide upgraded horsepower and a 55 AMP alternator (1GM10 35 AMP). Special Note: If your engine serial number starts with an "E" you must make sure that you use parts for the YEU engines. For example, if you have a 2GM20 with a serial number starting with E you actually have a 2GM20YEU. The (YEU) engines are European manufactured and now more common in the United States than the Japan built models. This series includes the following engines:
| Engine | HP | Years In Production | Comments |
| 1GM10 | 9 | 1983 - Present | Raw Water |
| 2GM20 | 18 | 1983 - Present | Raw |
| 2GM20-YEU | 18 | 1997 - Present | |
| 2GM20F | 18 | 1983 - Present | Fresh |
| 2GM20FYEU | 18 | - | . |
| 3GM30 | 27 | 1983 - Present | Raw |
| 3GM30-YEU | 27 | 1997 - Present | |
| 3GM30F | 27 | 1983 - Present | Fresh |
| 3GM30F YEU | 27 | - | |
| 3HM35 | 34 | 1983 - 1992 | Replaced with 3JH2 |
| 3HM35F | 34 | 1983 - 1992 | Replaced with 3JH2 |