48 HT25 - TRENCHING SETUP 4. Adjust throttle and drive to starting point. Move in line with planned trench. 7. Check that digging chain control and track controls are in neutral. 8. Check that boom is in line with planned trench. 6. Lower boom to just above the ground. 1. Fasten and adjust seat belt. 2. Start tractor and adjust throttle. 3. Raise boom and backfill blade. p 5. Lower backfill blade.