I have Bobcat 751F with a Kubota diesel. It starts perfectly fine and will run great for about 10 minutes. Then it starts sputtering or stumbling and stalls. If you try to restart the motor it will sputter or stumble and will not start. If I crack the nuts on the high-pressure injector lines, at the cylinder head, and crank the motor, air bubbles squeeze out around the nuts. Titghten the nuts and restart and it starts right up and runs for 10 minutes or so then starts sputtering or stumbling and stalls. Rinse and repeat, rinse and repeat. Anyone have advice on how to trouble shoot or have seen this issue? Any help is appreciated.