621 TRACTOR-SCRAPER Starting The Engine Caterpillar

1. Move transmission control to NEUTRAL.

2. Push brake control to PARK, if so equipped.

3. Move scraper controls to HOLD.

4. Push cushion hitch control to LOCKDOWN. Stay clear of hitch area.

5. Turn disconnect switch ON.

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Never turn disconnect switch off when engine is running.

6. If starting difficulty is encountered, pull out the rack limiter control knob about 2" (5 cm). As soon as the engine runs smoothly, return control knob to its original position.

Above 60°F (16°C)

7. Depress accelerator just past detent.

8. Turn switch to start. Release switch when engine starts.

Below 60°F (16°C)

7. Depress accelerator just past detent and turn switch to HEAT for indicated time (see chart).

8. Turn switch to START. Release when engine starts.

When Starting Fluid is Required

7. Depress accelerator just past detent.

8. Turn switch to HEAT for time indicated.

9. Turn switch to START and spray starting fluid sparingly into precleaner while cranking.

10. When engine starts, it may be necessary to return switch to HEAT until engine runs smoothly. Release switch.

Starting With Boost

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Attach ground cable last, and remove first, to prevent sparks from occurring near the battery which could cause battery vapors to explode. Attach ground cable from booster battery to a point away, and below, the battery on the machine to be started.