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2002 Mercury 90hp 2stroke over oiling

I am not familiar with the inside of the oil pump. It could be a gear to gear displacement pump or it could be a roller and a tube whereby as the crankshaft turns it rotates the gears with precise oil measurement or the roller wheels rotating against the tube full of oil.....less accurate I'd say.

As long as the crankshaft is turning you are adding oil to the fuel line. Question is, is there gasoline in the line too or hasn't it made it up the line yet. These new EPA mandated fuel lines with the overly stiff bulb make it hard for me to get a stiff bulb/determine the fact that the line is full of gasoline like one could get with the old diamond shaped Mercury fuel line bulbs that, when the carbs and line are full, it goes from mushy to hard within a squeeze or two.

Other thing that just hit me is that when priming with the bulb for the initial start, filling the bowls on the carbs and the fuel line, the crankshaft isn't turning so you aren't adding any oil when initially priming and getting a stiff bulb. Once you start cranking with your carburetor full of gasoline only (maybe a dab of oil left in the carb from the last run) the oil pump starts supplying oil to the gasoline. So if my thought is correct, for seldom boaters, the initial RPMs encountered when the engine starts are void of oil.

My reason for going with premix is that I only boat every few months. It takes awhile to get gas up to the carbs. While squeezing the bulb, cranking and choking, with inadequate gas to cause an explosion, oil is present because the crankshaft is turning and when enough gas enters the line to light off, the excess oil comes out as a cloud of smoke. Premix solved both problems... limited oil supply and too much oil.
 
The factory manual has a procedure to check output of the pump.-----Too much to type here for me.----Get a dealer to check this out.-----As usual I state that oil and lubrication in 2 strokes can be a big mystery for many folks.
 
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