Honda BF50 (5HP), BF5A Outboard Motors Shop Manual 2014, Page 83Get this manual
BF50BF5A 1LUBRICATION SYSTEM 2COOLING SYSTEM 3POWER TRAIN 4FUEL SYSTEM 5NEUTRAL START SYSTEM 6THROTTLE OPENER SYSTEM 7HALF THROTTLE SYSTEM
1LUBRICATION SYSTEM
aOIL CIRCULATION
The oil pump draws oil through strainer in the oil pan and supplies it under pressure to the lower main bearing and con necting rod journalOther engine parts receive lubrication from the oil that is thrown off the crankshaft either directly in the form of splash lubrication, or indirectly in the form of oil mistThe breather chamber, located at the upper main bearing, allows crankcase ventilation while preventing air that leaves the crankcase from taking oil with it
bOIL PUMP
The oil pump is trochoid type and consists of an inner rotor, outer rotor and pump bodyThe inner rotor is driven by the camshaft and causes the outer rotor to turn with itAs ,this happens, the spaces between the rotor lobes become filled with oilThen, when the lobes of the inner rotor move into the spaces in the outer rotor, the oil is squeezed out through the outlet, When the pressure rises to the preset value (3.5 0.4 kgcm50 5.7 psi), the check valve opens and oil flows back to the oil pan,