| 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} | 
| 350 |  | .~.~ Electrical sensing or regulating {3} | 
| 351 | DF | .~.~.~> Engine overspeed sensing with an indicator or alarm and speed regulation | 
| 352 | DF | .~.~.~> Engine speed sensing having an error signal producing circuit {7} | 
| 362 | DF | .~.~.~> Cold engine control |