Yes,the older Yanmars do run a bit...rough. The flywheel wieghs like 2 tons so when you decompress them to stop them they just chug-chug-chug till they quit moving..if you let go the decompress before they come to a complete halt-they start right back up.With rubber mounts the vibration is ok..though the noise is terrible if your in the cabin.I'd hate to be near a boat with solid motor mounts that had one of these in it.lol