Finally got my new (to me) boat that came with a 1998 200 Merc Offshore EFI (S/N OG724369) on the water to see how everything works. Started the motor and it idled very smoothly with very little smoke for about 5 to 7 minutes. My friend even said that he was surprised how smoothly and quietly it ran. Put the boat in gear and ran it for about 10 minutes at various speeds including WOT and noticed no change in engine sound or notice any excessive smoke. Stopped the engine and tilted it up to check a couple of things not related to the motor. All of a sudden I noticed a fair amount of 2 stroke oil had leaked from engine into the splash well. I thought this was odd, because at home when I tilted the motor up and when I hauled the boat to the lake no oil leaked from the engine. I then started the engine, but it smoked very badly and I could not rev it up much above idle. Took the cover off the engine and noticed some oil around the oil cap on the engine oil tank and in the bottom of the engine housing. So I tightend the cap, put the cover back on, and started it again with the same results, lots of smoke and unable to get the revs up. At home I had a closer look at the engine and I noticed a T brass fitting where one barb has nothing attached to it, Where to my way of thinking either a hose or plug should go. The hose that goes into the top of the T fitting comes from the engine oil tank and the hose that is conneced to the middle of the T goes to the port side of the engine, but there is nothing connected to the bottom of the T. I could not find a loose hose or see a plug laying in the motor. Anyone got any idea what the problem may be? See the attached picture.
