Suzuki outboard motors 1988 2003 repair manual., Page 194Get this manual
6-2 OIL INJECTION between engine rpm and the pump means that oil is metered without hesitation in exactly the correct ratio at all throttle openingsTo minimize smoke and possible carbon build-up at idle speeds Once the oil leaves the Mikuni pump, it travels through oil lines to distribution nozzles located downstream of the carburetor or throttle bodyThe nozzles then inject the oil directly into the incoming airlfuel mixtureThis thoroughly mixes the oil, air and fuel before it enters the combustion chamber in order to provide optimum lubricationSuzuki is the originator of outboard oil injection, introducing it to the marine industry in 1980Because of years of experience in motorcycle oil injection technology, Suzuki applied many of those proven principles to their outboard motorsThe oil injection system automatically adjusts the amount of oil to clean burning 150:l fuelloil ratioThen as engine rpm increases, the ratio changes gradually to 50: mixture at full throttle for greater lubricationAIRIOIL MIXING VALVE
See Figure 3
OIL PUMP
See Figures and 2
The heart of oil injection system is precision die cast Mikuni oil pump which is gear driven directly by the engine's crankshaftThis mechanical link
On some models, pre-atomization or mixing valve allows small amount of crankcase pressure to be injected into the oil lines just before oil reaches the distribution nozzlesThis forces thousands of tiny air bubbles into the oil flow before it gets to the combustion chamberThe atomized oil stream is therefore more uniformly distributed throughout the engine for superior lubricationAir-oil mixturecrankcase)