GM 4.3 V-6 Oil Slick

[regulator]

Started noticing an oil slick behind the boat while trolling. Ran motor on the ears and had that oily film in the run-off, and am thinking I'm getting some oil blow past the rings. Any other ideas? Thanks in advance!

[lakebound88]

Try a basic tune up... fuel will do that especially if she's nor running hot enough with a clean spark. Cap rotor and pkugs may be in order..

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[Chas0218]

Try a basic tune up... fuel will do that especially if she's nor running hot enough with a clean spark. Cap rotor and pkugs may be in order..

Sent from my SCH-I545 using Lake Ontario United mobile app

Yup this ^. I had the same issue with my outboard new plugs were the trick.

[regulator]

Thanks guy's, I'll start with the plugs!

[Xxx]

After that give it a can of Sea Foam in the gas. It will loosen up gummy rings, less blow by, when engine is hot how much air comes out the valve cover breather?

[lakebound88]

Remember, check that cap. If it has growth, replace it.

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[regulator]

Remember, check that cap. If it has growth, replace it.

Sent from my SCH-I545 using Lake Ontario United mobile app

Lakebound, I have the cap, rotor, plugs, and wires on the way. I noticed on the original cap there is a fitting at the bottom that appears a vacuum line could be hooked to. If you would be so kind, could you elaborate?

 

Thank you! 

[lakebound88]

Those were used for a system with vaccuum advance timing I do believe.

How did your current set look? A bit green?

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[L&M]

If it's Mercuiser the 90* fitting pointing down is to vent the cap of moisture, nothing should be or is attached to it.

[regulator]

Really appreciate the replies gent's. Yes, Mercruiser and thank you again for the explanation. The fitting on mine is discolored, but appears to be more just typical grime than green. I will be replacing it just the same when I do the plugs and wires.

[lakebound88]

What I'm asking is green is if the contact points under the cap are corroded. I do my caps almost once every season or every other depending on hours of use

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[Xxx]

Just a thought, I'm in the mist of going over a lower unit I purchased for my boat and there are 3 seals that can fail and let the outdrive leak oil which could cause oil to get into the water also, so just for safety sake check your oil level in your lower unit. There are 2 seals in the upper half and one in the lower part, the prop shaft seal, and the 2 in the upper half keep the oil in the upper gear set and the other keeps the water in the lower side from reaching the upper gear set kind of like a double protection plan, both unit I took off my original unit and the one I purchased had the water seal shot and the oil seal was on its last leg. Like I mentioned earlier just a thought. Hope your on the right track, this is hell what I'm going through right now!

[regulator]

Thanks Pap, gear oil seems fine. Looking more and more like unspent fuel. Had an issue on the water this weekend while trolling after trolling for several hours, when pulled the engine back to idle, she shut down. Cranked and cranked to get it restarted and when she did, it blew a cloud of carbon out the size of the boat!

[Xxx]

Well that's the lesser of the two evils, I threw that in only because of my situation, I truely believe your on the right track especially if it's puffing smoke like that after a restart. You'll be fine after a good tune up.

[regulator]

Yeah, good luck to you with that. All of my replacements are easy to get to.