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Water In Oil with pictures, looking for opinions

Yeah I agree but boat was out of the water on a lift so didn't want to run more than 10 seconds. Oil in the tank went from fresh oil to milky so it mixed.

Good tip about checking clearance. Need to check the accuracy of my compression gauge also. This motor turns 300 rpm more than the other one and it's new so would be surprised if the low compression reading was accurate.
 
Drain all the oil. It's super hard to remove milkshake by doing small tank changes. There is a full drain thread and a difficult bolt to get to, but i would start there and add oil until it comes out clean. My boat had low compression and milkshake oil, but they were unrelated. The po probably drove with just one engine, or flushed it wrong before i picked it up.
 
Well I would have bet it wasn't the gasket but ran the boat hard for around 6 hours this weekend and oil is water free. Seems like it takes a very small exhaust gasket leak to get water in the oil. Will keep an eye on it though.
 
@Yellowbird911 Your discovery is important for the water in oil syndrome. Thanks for posting.
 
Drain all the oil. It's super hard to remove milkshake by doing small tank changes. There is a full drain thread and a difficult bolt to get to, but i would start there and add oil until it comes out clean. My boat had low compression and milkshake oil, but they were unrelated. The po probably drove with just one engine, or flushed it wrong before i picked it up.

Complete oil change including the oil cooler. https://jetboaters.net/threads/oil-change-on-mr-1-how-to-perform-a-complete-drain.3805/
 
Interesting that this motor produces 300 higher rpm than the other one which is new from Yamaha which can be caused by the pump also. The Harbor Freight compression gauge must be off, surprise. Will continue to monitor but so far oil is clear and water free. Now for some sound compression work, damn this thing is loud. Coming from a 4.3 I/O I about need ear plugs. Have to turn radio way up and still hard to hear but that's another topic.
 
Interesting that this motor produces 300 higher rpm than the other one which is new from Yamaha which can be caused by the pump also. The Harbor Freight compression gauge must be off, surprise. Will continue to monitor but so far oil is clear and water free. Now for some sound compression work, damn this thing is loud. Coming from a 4.3 I/O I about need ear plugs. Have to turn radio way up and still hard to hear but that's another topic.
It's just a different sound. Read up about soundeadening the engine area. I already started down that road and plan on doing more this winter
 
Something that surprised me was before heading to the boat ramp I dropped and secured the bimini, wow what a difference. Too bad because I'll take the noise over the sun cooking down.
 
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Well I would have bet it wasn't the gasket but ran the boat hard for around 6 hours this weekend and oil is water free. Seems like it takes a very small exhaust gasket leak to get water in the oil. Will keep an eye on it though.

Hello, wich gasket did you change?
 
@kamilo2000 See post #18. I think @Yellowbird911 used original exhaust gasket(s) with some RTV sealant to fix milky oil problem.
 
Got to the boat last night and of course USPS has lost my exhaust gasket. So as a temporary repair/ test I used a very thin layer of high temp rtv just around the actual exhaust ports. Also replace the scupper valve which is a fun job. Suctioned out the oil 4 times and the oil is still milky looking. Of course I am only pulling out around 2-2.5 quarts using the vacuum method but surprising the oil is not more clear after than many changes. Takes very little oil to make oil milky. Ran motor for around 10 seconds between oil changes and motor was out of water. As a test I put maybe 4 ounces of the used oil in a jug with a quart of new oil and shook it, viola milky oil about the same color. Will be using the boat this weekend and will monitor closely oil level. If oil level does not increase I will probably be putting 4-6 hours on the motor so if the oil level increases or does not take on a more oil color I will be pulling the motor on monday.

Can you point me out to where exactly the exhaust ports are?
 
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