If the tractor won't shut off again. Just pull the shut off lever on the injector pump. There is a solenoid the pushes this lever that normally shuts off the tractor.Had starting problem with 234 Hydro. Started troubleshooting the problem, once I got it started I could not shut the tractor off. I had to disconnect the fuel supply to shut the tractor off. Has anyone had this problem before? Any help would be appreciated. Thanks!