Water or fuel in oil / what to look for

[havewill22]

I have a 2006 AR230 with the twin MR1. Backstory: got the boat in December 2023, took it out a few times after fixing a lot of issues not engine related. (Was able to track down the original owner which is about 3 owners before me. Found out that he rebuilt the port engine with a sbt block about 8 years ago, I've heard horror stories using sbt. He said the engine compartment flooded and hydro locked the port engine. I do have an issue with the port engine but it can wait til after I fix the starboard engine). Sat for a few months to do upholstery, marine mats, and paint. Did an oil change as well. Took boat out 2 weekends ago to the sandbar, probably a 15 minute ride, engines seem fine til I reached the sandbar and slowed down to idle speed. Starboard engine temperature light came on and didn't catch it in time but it was either steam or white smoke coming out of the pee hole. Figured it was because it was idling and couldnt pick up enough water but port engine was running fine. Shut engines off and hung out for a few hours. Both engines started back up and rode back to the dock just fine. Checked oil when I got home and it was good.

Fast forward to last weekend, took the boat out to the sandbar again and both engines we're good, no temperature light and didn't notice anything out of the ordinary. Hung out for a few hours and when it was time to go, starboard engine wouldn't start. Good thing I have valves installed on the coolant line, ran with the port engine back to the dock. When I got home, checked the oil and it definitely looked like it had water mixed into it.

Was busy so it sat for a week til today, wanted to look around the engine and check before I decided to pull it. Took the oil cooler off and the oil didn't look like it did last week, wasn't milky, I know it was sitting and could've settled. It now has a really strong fuel smell. I tested the injectors with YDS and all 4 injectors clicked as it should, didn't remove and ohm checked it yet. I removed some of the oil into a glass and will let it sit for a bit to see if there's separation.

If it's not water but fuel, other than fuel seeping through piston rings, how else would fuel get mixed in oil? (Also will do a compression check and leak down test later)

I've read on other posts that injectors could test fine but when engine is running and idling, a injector could be stuck open or at any other rpm range. If it is indeed fuel in the oil and not water, I plan to swap ecu to the port engine to see if fuel gets mixed in to the oil and vice versa with the port engine ecu.

If it is water, I plan to pull the engine to inspect block, exhaust manifold, etc. Could it be both fuel and water?

Picture of oil in glass jar is when I sucked it out and only been sitting for a few minutes. Will wait a few days to see what it looks like. Picture of oil in engine is after the boat sat for 7 days.

Any input would be appreciated, I've read lots of threads on this forum regarding water or fuel in oil but wanted to start my own thread for further tips and advice. Happy Father's day!

 

[Acard7]

The overheat you had probably was just something was sucked up, cavitated, and your intake screen was affected hampering your cooling system, at idle you may not notice there’s something in the pumps. When I sucked up a few things at different times while at no wake speeds I didn’t know I did until I throttled up and then I could feel the vibration and loss of power.

When you say the starboard wouldn’t start, did it turn over at all? Or just turned over and didn’t fire up?

The oil in the jar looks suspect, but be interesting to see how it looks when you post another pic..

 

[havewill22]

The overheat you had probably was just something was sucked up, cavitated, and your intake screen was affected hampering your cooling system, at idle you may not notice there’s something in the pumps. When I sucked up a few things at different times while at no wake speeds I didn’t know I did until I throttled up and then I could feel the vibration and loss of power.

When you say the starboard wouldn’t start, did it turn over at all? Or just turned over and didn’t fire up?

The oil in the jar looks suspect, but be interesting to see how it looks when you post another pic..

It would turnover but not start, on that day when I got home, I was able to start it by finessing the throttle but didn't keep it running any longer than 10 seconds in case it wasn't getting lubrication.

 

[Babin Farms]

Does the oil smell like gas?? Pull the spark plugs and crank it over with the lanyard pulled and see what blows out of the cylinders. Hard to tell if the oil in the jar is aerated or has gas/water in it.
When were the spark plugs changed? When was the oil last changed?

I stick my head over the side of the boat making sure the pissers are working as they should while underway probably enough to make people think I’m crazy. I also like to hear the engines while underway instead of cranking the radio up. Always listening or feeling for something that’s not right.

 

[Acard7]

I stick my head over the side of the boat making sure the pissers are working as they should while underway probably enough to make people think I’m crazy.

I will join the crazy club with you as I look numerous times while underway. ???

 

[havewill22]

Does the oil smell like gas?? Pull the spark plugs and crank it over with the lanyard pulled and see what blows out of the cylinders. Hard to tell if the oil in the jar is aerated or has gas/water in it.
When were the spark plugs changed? When was the oil last changed?

I stick my head over the side of the boat making sure the pissers are working as they should while underway probably enough to make people think I’m crazy. I also like to hear the engines while underway instead of cranking the radio up. Always listening or feeling for something that’s not right.

Yes the oil does smell like gas, I'm only second guessing because a week ago, the oil was milky and almost like a shake with very light brown color. I'll do a compression as well as pull spark plugs and crank it when I have some free time.

Oil and spark plugs were changed in February. I'm also the same, when I'm underway, I constantly check for water coming out the pissers.

 

[Babin Farms]

I will join the crazy club with you as I look numerous times while underway. ???

Doesn’t help if they're on that the dummy lights are too small, the wrong angle to see & always have a glare on them. Yamaha’s engineer must’ve been about 3.5ft tall when standing at the helm deciding on placement of the warning lights.

 

[finnrigged]

Did you ever figure out what the problem was? I've had fuel in my oil before on the same motor except in a WaveRunner and I've had water in my oil on the same motor except a waverunner. Your oil looks like fuel mixture to me but?? Whenever I have had water in my oil it always ends up looking more like a white striped mixture of goo.

Tried to keep up with your post in reading it but got a little bit lost at one point. I've had steam come out of pissers before but that has always been due to the cooling water not flowing through the cooling jackets inside of the hot exhaust or motor compartments. It's basically got a little water in there so it's cooking off like a steam iron. If that problem was never resolved or did not self resolve ( I do like the theory and possibility that something got temporarily sucked in to your jet pump where that water feeds into a screen and then into the cooling system). If not possible crack in one of the cooling hoses that you're not noticing while underway but spraying water all over inside the motor compartment? Run it with the compartment open and keep a watch inside when the RPMs get higher to see if a second person can see any water spraying around down there. Regarding the fuel in the oil, assuming that is what it is, you can pull off the top of your airbox cover and remove the Allen head shiny bolts that hold on the spark arrestors on all four cylinders. Very easy to remove and replace. Remove all four of your spark plug wires so that there's no possibility of an ignition Spark, hold open the butterflies on the throttle body manually and blip the key for a half second. That will trigger the fuel pump to do a momentary squirt of fuel into one or two of the cylinders at the very most. What you are then looking for is to see if the injector on one of those four cylinders continues to spray which would last approximately 5 or 10 seconds if one of your fuel injectors is stuck in the open position or if the ECM fuel injector relay is bad for that cylinder. I had this happen on a Yamaha FX high output Waverunner before and I immediately suspected the ECM because of all of the reading a person can do on that. What it actually turned out to be is the actual fuel injector was stuck in the open position. I replaced the fuel injector and it never gave another problem.

Another thing to look for regarding the steam coming out of your pisser issue... I believe you may have mentioned one of those Motors is an SBT remanufactured motor. When someone pulls their core motor out they send the stripped down motor to SBT and they get a remanufactured one in exchange. I've seen it before that when someone is reassembling the remanufactured SBT motor in the boat they forget to install the simple o-ring that slides around the bottom post of that large 90° angle bent stainless steel tube coming out of the top of your cylinder head. There is only one Allen head bolt that holds that thing in so it's very easy to inspect to see if that O-ring is in place. If it is not, Cooling water would typically be gushing out of that area around the base of it but that is actually the exit for the water as it heads to the back of your boat so it does not sound likely in this case since you have a steam issue indicating there is no water going to that exhaust or motor. However, alternatively, if you did find that it is water intrusion in your oil and not gasoline then it has also been a problem that SBT has sold cheap Chinese slightly undersized O-rings that go around that same post bottom. Depending on how well the cylinder head cover gaskets is installed where it makes the water Tight Seal in that same Nook water could be coming up that hole and backfilling into your cylinder head. This would be easy to figure out though because all you need to do is take a pick and pry up that rubber black gasket that surrounds the base of the stainless steel pipe where it comes out of your cylinder head cover. Fire up the boat on the water, not on a garden hose, give it some RPMs and see if you have any water coming up out of that hole down inside where that single Allen head bolt secures. If there's any water that comes up in there something is wrong because it's a dry area.

Hopefully by now you have solved all of your problems but I thought I would throw this stuff in there in case anybody does a future search for information having the same problem