Oil in Carbs?

Fishin' Rod

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I had a problem with oil in my carbs in my 200 hp Merc OB this weekend. I hadn't run my boat for the last 2 weeks and when I went to use it this weekend I couldn't get it started. I eventually call my Merc mechanic and after making sure it wasn't related to other problems it was determined that the carbs were filled with oil. One of the first things I noticed is when I went to pump the primer bulb it was hard as a rock (the carbs being clogged with oil probably was the cause of this). I had recently replaced one of the clamps on the primer bulb due to a small leak and though that I had an airtight situation. Wishful thinking I though. When I had removed some of the fuel from the fuel lines going to the carburetor I noticed that it was pretty much the same color as the Quicksilver 2 cycle oil I use. It still had the consistency of gas though. Anyway, he ended up draining the carbs and cleaned them out with carb cleaner.

Now I have been using Startron fuel additive but no more than recommended. My mechanic suggested I stopped using it for awhile until I thin out my mixture of gas with new gas. Another thing, it has been over 90° for quite a few days and with the engine tilted up is it possible that the gas evaporated leaving only the oil behind? But if that is true then how can I explain the color of my fuel being like my 2 cycle oil? And I haven't been using more oil than usual.

Any help or suggestions will be greatly appreciated.
 

gw204

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Not sure why it wouldn't start, but it's normal for the gas to be that color. The carbs are down stream from the oil injection pump so the gas and oil get mixed before being delivered to the carbs.

Is your choke working properly?
 

Fishin' Rod

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gw204 said:
Not sure why it wouldn't start, but it's normal for the gas to be that color. The carbs are down stream from the oil injection pump so the gas and oil get mixed before being delivered to the carbs.

Is your choke working properly?

I think so, I've used it to start the engine without a problem since then. I'm still wondering why the fuel would be so dark. When I say dark as the color of the oil I mean that you can not see thru it. And the primer bulb was hard as a rock without squeezing it. I'm assuming it was due to the carbs having oil in them which created a blockage.
 

gw204

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Even if the carbs had straight oil in them, I don't think the oil is thick enough to block up the system.

Check the linkage on your oil pump. If I remember correctly, a Merc oil pump defaults to full capacity if the linkage fails.

I would also take the primer bulb out of the system and check it. Maybe one of the valves inside failed.
 

BobP

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Could it be possible the fuel / oil pump is only pumping oil ?

Is it possible the oil then went back via the fuel line feed?

Does motor fire at all or dead as doornail?

The fuel squeeqe bulb shouldn't be hard, unless you first pumped it normally then it hardened up.
 

Fishin' Rod

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gw204 said:
Even if the carbs had straight oil in them, I don't think the oil is thick enough to block up the system.

Check the linkage on your oil pump. If I remember correctly, a Merc oil pump defaults to full capacity if the linkage fails.

I would also take the primer bulb out of the system and check it. Maybe one of the valves inside failed.

3 carbs with oil in them could make the flow of fuel very hard. I wasn't there when the mech drained them so I couldn't say how thick the oil was. I am only going by what he told me. As far as the linkage I will have to look into that. And for the primer bulb I switched it with another to make sure it wasn't that.
 

Fishin' Rod

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BobP said:
Could it be possible the fuel / oil pump is only pumping oil ?

Is it possible the oil then went back via the fuel line feed?

Does motor fire at all or dead as doornail?

The fuel squeeqe bulb shouldn't be hard, unless you first pumped it normally then it hardened up.

1. Can't answer the 1st question.

2. The motor turned but wouldn't catch like it was not getting any fuel.

3. The primer bulb was hard as a rock when I first attempted to pump it. I am assuming it was because the carbs were clogged with oil.