| 123 / | HD | INTERNAL-COMBUSTION ENGINES |
| 319 | DF | ENGINE SPEED REGULATOR {16} |
| 349 | DF | .~ Having condition responsive means with engine being part of a closed feedback system (e.g., cruise control) {4} |
| 378 | DF | .~.~ Fluidic sensor or regulator {6} |
| 393 | | .~.~.~ Responsive to exhaust gas |