Westerbeke 12.5 Generator Set

⚠ Never attempt to adjust fan belt tension while engine is in operation.

1. Depress belt with finger between pulley and pulley on long distance side.
2. Proper tension gives 10 to 12 mm (0.39 to 0.47 in) deflection.
3. Adjust excessive tension or slackness as needed.

1. Use antifreeze containing rust inhibitor from a reliable maker.
2. Never mix with antifreeze of a different brand.
3. Select concentration for a temperature about 5°C (10°F) lower than actual atmospheric temperature.

1. Discharge old oil through sump drain hose at front of engine while engine is still warm.
2. Drain old oil completely.
3. Replace hose and plug end securely.
4. Add fresh oil through oil inlet port on valve cover.
5. Idle engine several minutes and stop.
6. Check oil quantity by oil level gauge; fill to but not over high mark.

1. After first 50 hours, loosen retainer ring #16 and discard filter element #15.
2. Clean bowl #17.
3. Install new filter using new gaskets #13 and #14.
4. For fuel lift pump, replace filter element #6 using new gaskets #7 and #8.
5. After first 50-hour change, increase change period to 200 hours or once per season.

⚠ Aftermarket filters are not recommended.

1. Apply engine oil thinly to O-ring.
2. Install oil filter and tighten by hand firmly.
3. Cover used filter with plastic bag when removing to collect element and spilled oil.
4. After filter change and oil fill, run engine and check oil pressure and leaks.

1. Fill engine oil to near upper dipstick limit with API CC or better oil.
2. Fill engine coolant to neck of manifold cap.
3. Fill recovery tank to bottom level line.
4. Fill fuel tank with diesel fuel and keep clean.
5. Check engine oil, coolant and transmission levels at least once daily before use.

1. Depress preheat switch 15 to 25 seconds to energize electric fuel pump and purge accumulated air.
2. If engine cannot be started easily, loosen two injection nuts on nozzle side.
3. Turn starter motor.
4. Tighten nuts firmly.

⚠ Overload is signalled by smoky exhaust and/or reduction in speed and voltage.

1. Service life depends on first 10 hours.
2. Do not break in at no load.
3. Immediately after start, add approximately 25% load for fast warm-up.
4. For first 10 hours, run between 20 and 60 percent load.
5. After 10 hours, load as needed but avoid overload at all times.
6. For next forty hours, use approximately 70% load.

1. Make certain oil viscosity is adequate for prevailing ambient temperature.
2. Check oil for deterioration.
3. Check battery is fully charged.
4. Allow glow plug to operate sufficiently to aid starting; see preheat table.

1. Depress preheat switch 15 to 25 seconds after lay-up, fuel filter service, or repairs.
2. Use preheat table: approx 10 sec at +5°C or higher; 20 sec at +5 to -5°C; 30 sec at -5°C or lower.
3. While holding preheat, depress start switch.
4. When engine runs, release start switch.
5. Continue holding preheat 2 or 3 seconds to defeat low oil pressure shutdown.
6. Release preheat switch.
7. Check oil pressure, battery charge voltage, and raw water discharge.
8. Warm up at reduced load until water temperature reaches 140 to 150°F.

1. Depress stop switch until engine stops completely.
2. Release stop switch.

⚠ Do not connect to AC terminals; this will destroy the rectifier.

Tools: alligator clips

1. Stop engine and remove generator end cover.
2. Locate field coil positive lead connected to + terminal of rectifier and negative lead to opposite unmarked terminal.
3. Using alligator clips, connect field coil positive to battery positive and field coil negative to battery negative for approximately 10 seconds.
4. Set will then build voltage and output.