Westerbeke 20.0 BED Generator Set

⚠ Never check or adjust the drive belt's tension while the engine is in operation.

1. Remove the belt guard.
2. Loosen the alternator adjusting strap bolt and the base mounting bolt.
3. With the belt loose, inspect for wear, cracks, and frayed edges.
4. Pivot the alternator on the base mounting bolt to loosen or tighten.
5. Tighten the base mounting bolt and the adjusting strap bolt.
6. Operate the generator about 5 minutes, shut down and recheck belt tension.
7. Replace the guard.

⚠ Adjust the valve clearance when the engine is cold.

Tools: Feeler gauge, Wrenches

1. Retorque the cylinder head bolts before adjusting valves.
2. Pull off the air breather pipe, remove rocker cover bolts and rocker cover.
3. Position No. 1 piston at TDC on its compression stroke; adjust valves #1, 2, 3 and 6.
4. Position No. 4 piston at TDC on its compression stroke; adjust valves #4, 5, 7 and 8.
5. Valves are numbered 1 to 8 from the front of the engine to the back.
6. Set each valve to 0.012 inch (0.3 mm) with a feeler gauge while the engine is cold.

⚠ A failed alternator can become very hot; do not touch until cooled.

⚠ Do not use a high voltage tester (e.g. Megger) on the alternator charging circuit.

Tools: Multimeter

1. Start the engine.
2. After a few minutes, measure starting battery voltage at the battery terminals with a multimeter on DC volts.
3. Voltage should be increasing toward 14 volts; if so, alternator is working.
4. If voltage remains around 12 volts, stop engine and inspect all wiring and connections.
5. Check battery voltage with ignition on and engine off; should be 12 to 13 volts.
6. Check voltage between alternator B+ output and ground with engine running; should be 13.5 to 14.5 volts.
7. If only battery voltage at B+, check for 12 volts DC excitation at the EXC terminal and trace wiring.

⚠ Glow plugs are energized during preheat bleeding; do not overheat them.

1. Open the bleed screw on the filter housing one or two turns.
2. Energize the preheat switch for 10-20 seconds, or slowly depress and release the primer pump.
3. Force air out through the bleed point until all air is expelled.
4. Tighten the bleed screw.
5. Repeat preheat or primer pumping to purge air between filter housing and injection pump.

Tools: Wrench, Towels

1. Open the bleed screw on top of the fuel filter.
2. Unscrew the knob on the fuel feed pump; the cylinder will pop up.
3. Work the priming pump with full strokes until free of air bubbles.
4. Close the bleed screw.
5. Disconnect the fuel return hose, place towels, and pump until clear fuel discharges.
6. Reconnect the return line and work the pump a few more strokes.
7. Start the engine and check/correct any leaks.
8. If running is unstable, loosen each injector high-pressure line 1/2 to a full turn to expel air, then retighten.

⚠ The cartridge contains fuel; take care not to spill it during disassembly.

Tools: Filter wrench, Rag

1. Shut the fuel supply off.
2. Loosen the fuel filter turning counterclockwise with a filter wrench.
3. Wipe clean the sealing face on the housing bracket.
4. Lightly oil the sealing o-ring on the new filter.
5. Turn filter clockwise until the o-ring contacts the sealing surface, then turn 2/3 further.
6. Turn on the fuel and start the engine; prime the system if it fails to start.

Tools: Container

1. Shut off the fuel supply.
2. Open the bleed screw on top of the filter and drain the bowl.
3. Close the drain and unscrew the bolt securing the bowl; bowl and filter drop down.
4. Clean the base and install a new sealing ring squarely in the base recess.
5. Replace the upper sealing ring and the o-ring in the filter head.
6. Install the new filter element and re-install the retaining bolt.
7. Bleed the air from the filter assembly.

⚠ If any vanes have broken off, find them to prevent blockage in the cooling circuit; they are often in the heat exchanger.

Tools: Two small screwdrivers

1. Close the raw water intake valve.
2. Remove the pump cover.
3. Carefully pry the impeller out of the pump with two small screwdrivers.
4. Install the new impeller and gasket, moving blades to conform to the curved cam plate.
5. Apply a thin coating of lubricant to the impeller and gasket.
6. Open the raw water intake valve.

⚠ Used engine oil contains harmful contaminants; avoid prolonged skin contact.

Tools: Filter wrench

1. Run engine until warm, then shut down.
2. Discharge used oil through the sump drain hose; replace hose in bracket and cap securely.
3. Remove the old oil filter; confirm the rubber sealing gasket comes off with it.
4. Wipe the filter sealing surface on the engine block free of oil.
5. Apply a thin coat of clean engine oil to the new filter gasket.
6. Screw the filter on and tighten firmly by hand; do not over-tighten.
7. Fill with new oil to, but not over, the high mark on the dipstick.
8. Run engine and check oil pressure and for leaks around filter and drain.

⚠ Do not leave old engine oil in the sump over the lay-up period.

1. Drain all engine oil, replace the oil filter and fill sump with new oil.
2. Top off fuel tank with No. 2D diesel and add fuel additives; change filter/water separator element.
3. Flush raw water circuit with fresh water then antifreeze solution.
4. Remove raw water pump impeller; store it and replace cover with a new gasket.
5. Check and clean or replace zinc anode; clear zinc debris from heat exchanger.
6. For long lay-up (12 months or more), remove glow plugs and squirt oil into cylinders.
7. Rotate crankshaft by hand two revolutions and re-install glow plugs.
8. At recommissioning, install impeller, reconnect batteries, check zinc anode and start engine.

1. Remove the cap screws and disassemble the thermostat housing.
2. Apply a thin coat of sealant on both sides of the new gasket.
3. Press the gasket into place and install the new thermostat.
4. Reassemble the housing; do not over-tighten the cap screws.
5. Run the engine and check for normal temperature and no leaks.

⚠ Prolonged cranking can fill the exhaust system with raw water and damage the engine.

1. Complete prestart inspection and switch all AC loads OFF.
2. Depress PREHEAT: approx. 10 seconds at +41°F (+5°C) or higher.
3. Preheat approx. 15 seconds from +41°F (+5°C) to +23°F (-5°C).
4. Preheat approx. 20 seconds at +23°F (-5°C) or lower; limit continuous use 30 seconds before cranking.
5. While holding PREHEAT, depress START to engage the starter solenoid.
6. Release START when engine starts; hold PREHEAT until oil pressure reaches 15 psi.
7. Check gauges for oil pressure and battery charging voltage.
8. Warm engine 5 to 10 minutes to 140-150°F (60-66°C) before applying heavy loads.