WESTERBEKE GASOLINE GENERATOR

ENGINE COOLING CIRCUITRAW WATER PUMPThe raw water pump is a self-priming, rotary pump with anon-ferrous housing and a Neoprene impeller. The impellerhas flexible blades which wipe against a curved cam platewithin the impeller housing, producing the pumping action.On no account should this pump be run dry. There shouldalways be a spare impeller and impeller ccver gasket aboard(an impeller kit). Raw water pump impeller failures occur whenlubricant (raw water) is not present during engine operation.Such failures are not warrantable, and operators are cautionedto make sure raw water flow is present at start-up. The rawwater pump should be inspected periodically for broken ortom impeller blades. See MAINTENANCE SCHEDULE.RAWWATER INHEAT EXCHANGERCool raw water flows through the inner tubes of the heatexchanger. As the engine coolant passes around these tubesthe heat of the internal engine is conducted to the raw waterwhich is then pumped into the exhaust system and discharged.The engine coolant (now cooled) flows back though theengine and the circuit repeats itself.The engine coolant and raw water are independent of eachother; this keeps the engine's water passages clean from theharmful deposits found in raw water.TO ENGINE BLOCK~t FROM RAW WATER PUMPtHEAT EXCHANGERGASKET1ZINC ANODECOOLANTDRAINFROMGASDENSERtTO HEATEXCHANGERRAW WATER PUMPCHANGING THE RAW WATER PUMP IMPELLERNOTE: Coat the replacement impeller blade tips with petroleumjelly before installing.A CAUTION: The raw water intake valve (seacock)must be closed when servicing any components of theraw water system, and must be re-opened before startingthe engine.NEWREPLACEZINC ANODESREPLACECLEAN ANDREPLACEEND CAPA zinc anode (or pencil) is located in the raw water coolingcircuit within the heat exchanger. The purpose of the zincanode is to sacrifice itself to electrolysis action taking placein the raw water cooling circuit, thereby reducing the effectsof electrolysis on other components of the system. The conditionof the zinc anode should be checked monthly and theanode cleaned or repJaced, as required. Spare anodes shouldbe carried onboard. The area in the exchanger where theanode is located should periodically be cleaned of anodedebris. Take care not to lose the small O-ring that nestlesbetween the heat exchanger end gasket and the ccver.DRIVE BELT ADJUSTMENTA CAUTION: The drive belt must be properly tensionedfor the belt-driven water pumps to function properly.For the raw water pump/fresh water pump drive belt tensionadjustment procedure, see DRIVE BELTS ADJUSTMENTunder ENGINE ADJUSTMENTS.-.y- WESTERBEKEEngines & Generators14