Merc 200 EFI (2-stroke) -- WTF?

[skunkedagain]

My 2000 Merc 200 EFI (less than 200 hours) is doing a strange thing. After launching, it sat at the slip for 6 weeks (I just couldn't get out on the boat). When I finally tried to go out, the oil beeper sounded (beep-beep-beep). When my mechanic (a Merc dealer) checked it out, he found the on-engine oil reservoir was dry. He primed and filled it and said I was OK to go.

So, where did the oil go? No visible leak, so I'm guessing that it gravity-fed into the cylinders. (Hmmm -- is that why I get so much white smoke right after I start the engine?)

I don't use the boat that often, and expect that I'll be removing the cowl to check it before I try to start it again. How does one "prime" that reservoir? Just fill it with oil?

Edited July 17, 2010 by skunked_again

[synthnut]

My 2000 Merc 200 EFI (less than 200 hours) is doing a strange thing. After launching, it sat at the slip for 6 weeks (I just couldn't get out on the boat). When I finally tried to go out, the oil beeper sounded (beep-beep-beep). When my mechanic (a Merc dealer) checked it out, he found the on-engine oil reservoir was dry. He primed and filled it and said I was OK to go.

So, where did the oil go? No visible leak, so I'm guessing that it gravity-fed into the cylinders. (Hmmm -- is that why I get so much white smoke right after I start the engine?)

I don't use the boat that often, and expect that I'll be removing the cowl to check it before I try to start it again. How does one "prime" that reservoir? Just fill it with oil?

I had a similar situation with my older Merc .....Did you loose the oil from the reservoir on the engine, or the larger one that is in the boat ? ....If you lost oil from the one in the engine , I think I can help .....There is a small valve that is on the side of the engine that relieves the pressure once the engine is shut down for a bit ......When you run your engine, there is pressure that builds up that lets the oil get pulled along and the mixes with the fuel as you go along ....It's metered so to speak ....If the motor is shut down , and that relief valve does not work , oil is continuosly under pressure and pushes into the line to the engine ....Mine went so far after sitting a LONG TIME , that it went thru the motor and started it's way to the fuel tank ....I had to drain all my carbs (older motor) and Merc told me to loosen one of the caps on one of the oil tanks after shutting down the motor after I'm done using it to relieve the pressure ...All you do is loosen one of the oil caps and leave it that way until you use it again ....Make sure you tighten the cap back up again when you use your boat the next time or you will have oil all over the place .....This problem has not happened since .....Jiim

Edited July 24, 2010 by synthnut

[skunkedagain]

Thanks. Mine is an EFI, and, yes -- it's the onboard reservoir and not the 2 gallon tank below deck. I tried again today, after the boat sat a week or so after the shop reprimed it, and it was halfway down,. beep beep beep. Mechanic says there are a couple of check valves than can be troublesome, and one of them is supposed to keep the oil from flowing back to the big tank. This is the one he suspects is causing the problem. It's not going into the cylinders - there's no big white exhaust when I start up. Next week they'll pull the boat and try to figure it out. Damn engine still has less than 200 hours, and none this year! It's a 165 mile one-way drive to get to the boat, and this is starting to get annoying.He said "check valve" but maybe he's talking about the "relief valve" you mention.

Edited July 28, 2010 by skunked_again

[Gary_D]

There's no way that the oil can go directly to the cylinders. It has to mix with the oil upstream of the injectors and be injected with the firing of the injectors- can't happen with the engine off. if it backstreamed into the fuel line, you would have ~2 qts of solid oil in the fuel line when you next ran it and if it ran at all it would smoke big time. that leaves an external leak ( that you would see) or it siphoned back to the 3 gallon remote tank. I think there is a check valve in the pickup tube in the remote tank, I would be looking there. There might be one in the oil line before the oil pump (inside the engine cowling. Check there as well. You could probably clean them out with some spray carb cleaner yourself.