Cause of Engine Failure? 2014 Yamaha SX190

[Tkline]

We just purchased a 2014 Yamaha SX 190 Yamaha, being sold on consignment from a marina in MA, about 2 hrs away from us. The marina’s mechanics told us everything was perfect with the boat. We have been out for three one-hour rides over the past two weekends on the Hudson River. On the second trip, we started the boat and noticed a lot more vibration. We moved out of the slip to get gas and there was very little power and suddenly the engine started to smoke and the engine temp,alarm sounded. We shut the boat off, tied up, opened up the clean out port, and pulled out several large sticks thicker than my finger. We started the boat back up amd took it for a shake down and everything seemed fine. On our third trip out, after running the boat for about 45 minutes at 30 mph, my son was driving and opened up the throttle to pass a larger boat. The wake was very large and as we came over it, I think he pulled the throttle all the way back past neutral and into reverse.The motor stalled. We restarted the boat and continued on. Again, at about 30 mph, in about 10 minutes, the boat started surging and we slowed down and then noticed smoke. We opened The clean out port and I did not feel any sticks. We opened the hatch to check the oil and there was none on the dipstick. But in the cap there was a water emulsion, like mayonnaise. We called Sea Tow and we were towed back in. That is our situation now. I assume the oil is emulsified and sitting in the very bottom of the engine, but not registering on the dipstick. I’m wondering if anyone knows why this happened? Could we have blown a head gasket with the impeller being stuck by sticks, or is it possible for the engine to aspirate water when running wide-open and suddenly shifting into reverse? since i think the first case will lead to a new engine, i am hoping it is the second case and we can just have the engine cleaned out. I am hoping this will give us some information to give to the mechanics and hopefully we don’t need a brand new engine In a boat we have run for 3 hours. Thank you, ahead of time for your help and insight.

 

[Dave burke]

Geez sorry to hear that. I would start with a couple of things:

- check the impeller to see if anything is stuck in there. You’ll have to get under the boat to do this

- if there is no oil on the dipstick, that could just mean it’s low on oil but the mayonnaise effect worries me. Usually the only way water can get in the oil is if the engine is submerged. Your sons actions are unlikely to have caused it. And it’s possible it’s old emulsification but I wouldn’t bet the farm on that. I’d start by changing the oil and filter and seeing what the oil really looks like.

- the overheating could be caused by cavitation or something else. Once you’ve changed the oil and hopefully it’s running, make sure water is coming out of the pee hole.

I’d start with these things. I’m sure others have had similar issues will chime in. The closest issue I had was a few years ago when my sea doo Speedster started smoking because I had sucked up a bunch of debris. I thought the engine was toast but once I cleared stuff out, it was fine.

Good luck.

 

[buckbuck]

It is very unlikely sticks in the jet would cause this problem. Sucking up things is not uncommon for many of us and don't recall anyone having water in the oil due to it. Also, slamming a boat in reverse will not cause any problems. Some guys do it on purpose.
Change the oil and take it out again. Carefully monitor the oil condition. Don't go too far from the launch until you are confident you are not introducing water in the oil.
I know you said you saw smoke but is it possible it was steam. When the engine heats up due to cavitation it tends to have steam come out the ports. Yamaha has sensors that limit the rpm when the engine hits a high temp. It is unlikely you damaged anything.

 

[buckbuck]

By the way, welcome to the forum, @Tkline
We are here to help you enjoy your boat with the family.

 

[Cambo]

Did you check the oil or relied on the mechanic that he checked it ? It could have been low and milky to begin with. Running with cavitation is bad it does not allow for proper engine cooling the fact that a sensor was set off and the motor was smoking is not good internal items could be damaged allowing water into the oil. How long was it run with the sensor showing over heat? Throwing it in reverse is a non issue the impeller does not change direction there is no transmission just a gate that changes the water flow direction.

 

[Tkline]

Thank you, all. I checked the oil when we bought it, but trusted the mechanics when they said all was good. I do wonder if they changed the oil just to show it was clean. We have run it for only three hours. Waiting on local marina to check it over. The only issues are a stick in the clean out port and the full throttle to reverse in a half second.

 

[Tkline]

It was definitely smoke, though, not steam.

 

[14SX190]

We just purchased a 2014 Yamaha SX 190 Yamaha, being sold on consignment from a marina in MA, about 2 hrs away from us. The marina’s mechanics told us everything was perfect with the boat. We have been out for three one-hour rides over the past two weekends on the Hudson River. On the second trip, we started the boat and noticed a lot more vibration. We moved out of the slip to get gas and there was very little power and suddenly the engine started to smoke and the engine temp,alarm sounded. We shut the boat off, tied up, opened up the clean out port, and pulled out several large sticks thicker than my finger. We started the boat back up amd took it for a shake down and everything seemed fine. On our third trip out, after running the boat for about 45 minutes at 30 mph, my son was driving and opened up the throttle to pass a larger boat. The wake was very large and as we came over it, I think he pulled the throttle all the way back past neutral and into reverse.The motor stalled. We restarted the boat and continued on. Again, at about 30 mph, in about 10 minutes, the boat started surging and we slowed down and then noticed smoke. We opened The clean out port and I did not feel any sticks. We opened the hatch to check the oil and there was none on the dipstick. But in the cap there was a water emulsion, like mayonnaise. We called Sea Tow and we were towed back in. That is our situation now. I assume the oil is emulsified and sitting in the very bottom of the engine, but not registering on the dipstick. I’m wondering if anyone knows why this happened? Could we have blown a head gasket with the impeller being stuck by sticks, or is it possible for the engine to aspirate water when running wide-open and suddenly shifting into reverse? since i think the first case will lead to a new engine, i am hoping it is the second case and we can just have the engine cleaned out. I am hoping this will give us some information to give to the mechanics and hopefully we don’t need a brand new engine In a boat we have run for 3 hours. Thank you, ahead of time for your help and insight.

Any updates?
I lost oil pressure from a leaking oil cooler this weekend. Was't fun to find a bilge full of oil.

There is a lot of help and knowledge available on this site. All you have to do is post back findings.

 

[David Martin]

Usually water in oil that causes a milkshake/mayonnaise is always some type of gasket giving giving out. I always suspect the gaskets under the most pressure(Head gasket) or the gaskets under the a lot of heat(exhaust). My recent milkshake/ mayonnaise I thought was blown head gasket turned out to be upon tear down a crack in the head that evolved the exhaust valve seat............my symptoms were rough/vibration steam mixed with oil smoke.

After engine engine shut down on my lift the next day I removed plugs and read them The #7 was corroded and had rust(I boat in salt water) the water after shut down(engine get hotter during heat soak) allowed water to flow into cylinder and it would drain into oil past rings(it was a 21tear old engine at this point the rings were not tight to say the lease. This allowed my oil to mayonnaise result.

Hope this helps and I hope the they will help you out.......... but most times in a consignment sale the dealer will wash his hands.
HE might feel guilty and give you a good deal on tear down and repair BUT and a big BUT my confidence in a marina mechanic knowing all the details and difference of a Yamaha jet ski engine make me nervous. GOOD LUCK and I hate that you are a new 3 hour owner with this issue.

 

[WREKS]

I would try to return it.

 

[Betik]

Try to recall is the milky oils was before towing or after towing. A lot of people who are not familiar with these boats end of having water intrusion while being towed.

I understand there have been a few weeks since the incident but you will want to do enough oil changes until the oil is complete clean. This important because you most likely had salt water in the engine and you need all that flushed out in order to save the engine.


That being said I am not sure that anything you are describing would have caused issues in the damage. The reverse defianiately not an issue at all.
The first overheating from the sticks it could have caused issues but if you were quick to turn the engine when the heat alarm went off you should have been okay. Ours has had the overheat alarm go off at least 2 or 3 times without any known consequences.