Water in Oil

[Boyd95]

I’m having my engine replaced right now as well from a cracked block in my 08 sx230. I sucked up a bunch of mud and it clogged all the coolant lines. It over heated the motor and cracked the block. I had water in my oil as well. I never got any alarm of any kind indicating my engine was over heating. I did note the next day after sucking up the mud was the holes on the side of the boat where water normally sprays out we’re completly clogged with mud.

 

[Speedling]

https://www.shopsbt.com/jetski/yamaha-engine-fx-ho-ar230-ho-sx-230-ho-2004-2008.html

 

[Cody Jacobs]

I'm not understanding on how a crack in the outside of the block can cause oil water contamination. That looks like the coolant passages. Did they drain the oil or of the bottom of the engine?
View attachment 72341

It sounds like it could have been a separate issue or the crack was bad enough that it was shooting water out hard enough to get in the water box?

 

[Cody Jacobs]

Glad to have you on board @Cody Jacobs sorry we had to meet like this,

is this a Yamaha watercraft mechanic (PWC or Boat) a general marine mechanic or a car shop?

At $2200 I think I would cut bait and take it to a PWC shop to put a new engine in. It's going to cost you another $2k probably but at least you'll have a running boat, right now your at $2k with no end in sight (and I don't have a lot of confidence in what they're doing for you).

Thanks for the reply! Yes, this is a Yamaha Watercraft Mechanic. I talked more with the shop last week and come to find out Yamaha isn't producing these engines anymore and I would have to go with a 2017 motor... long story short the conversation was leading to a bill of over $10,000 so that's not going to be an option for me. I called another Yamaha dealer in town (Tulsa) and they confirmed that Yamaha isn't producing those motors anymore. I talked with another Yamaha mechanic about the SBT replacement motors and he says he does maybe 20/ year and hasn't been seeing any problems; however I just read a handful of reviews that is making me 2nd guess the SBT motors. Here is the link...https://forums.iboats.com/forum/gen...s-waverunners-etc/162082-beware-of-sbt-motors

Another option would be to have the motor rebuilt... I'm not sure the cost on that... sucks that lake season is so close and I don't have a decent plan on getting up and running yet.

 

[spatty99]

I have a rebuilt SBT MR1 with about 200 hours. Knock on wood still runs great and routine oil analysis look great. When I had mine rebuilt a few years ago I also found some negative SBT input, but it seemed limited to some older 2 stroke and/or carbureted engine types (that probably weren't the most reliable right out of the factory!).

 

[skyler baldwin]

Hey guys new to the forum and jet boating, just bought a 2007 sx230 with the mr-1 HOs. One engine was bad at the time of purchase so we are replacing it. Please see my pictures. Looks likes the cylinder closest to the oil reserve failed. What would cause the engine to malfunction and this to happen?Boat was kept on a lift in brackish water and guy claims he flushed after every use. Trying to figure out so i can prevent this from happening to my replacement. Thanks

 

[Jgorm]

Ouch! Usually it's detonation that will send a rod out the block. Clogged cooling or clogged injector would be my guess if the other plugs look good. If everything is lean then it could be other sensors or the fuel pump. Good luck with the build! Start a thread and keep us up to date.

 

[skyler baldwin]

Bought a used jet ski engine and am going to do a swap. Think the salt water deteriorated the cooling system and caused this? Thermostats were in rough shape

 

[Shallow runner]

Has anyone's motor survived after having water mix with the oil . I caught it immediately after noticing the boat running odd drained all of the oil out from the oil drain bolt at the bottom of the motor and sucked out the oil tank . Ran it for 30 second intervals oil was clean did not want to run it on the hose due to water getting in . Pressure checked the oil cooler it was good than pulled the manifold off while the motor was in the boat , Port side allows for removal of the 20 bolts, two clamps and multiple water lines difficult but possible. I was kind of relieved that it was not a cracked block or warped head and in fact the manifold water jacket issue on cylinder 4 and 2 . Picked up parts off ebay reinstalled ran it on the hose no water in the oil the motor sounds perfect.

Things I learned during the process :

It may be possible to pull the 4 water supply lines off the manifold put a balloon on each of the aluminum barbs run the motor for 10-20 seconds with no water and watch it inflate if you do have breach on the water jacket ,it should force a lot of air into the breach this is a theory I'm not sure if pressure down the line could create the same effect. If you have water in the oil and want to trouble shoot the issue this could be a good way to check . looking at the carbon in the water jacket its obviously pumping exhaust into the jacket.

The gap is about the size of one of the pee holes and from how fast the piston fires 99% must be exhaust gas being forced into the water jacket and a slight bit of water is getting into the cylinder not causing hydro lock but making its way into the oil. How that is possible I'm not sure.

re installing the lower manifold is difficult getting the alignment pins on the lower part and the rubber hose connection to all align at the same time . With help from my son we took a pole with a thin rope and used it to pull the lower manifold up into alignment, gravity and the rubber boot create an issue that makes it impossible to line up without something helping.

This seems to be the Achilles heel of the Yamaha boats if your boat starts running odd check the oil it may not be a fouled plug if water thins the oil to much the engine will self destruct. I run in fresh and salt water about 270 hrs I did have a few runs that I sucked up a small branch, sea grass and lake weeds that created cavitation and an engine light to register it did not go into limp mode just prompted me to pull over and reach in the port to clean out debris. The breach could have been from running hot maybe it incinerated the aluminum . It looks like all the new models have a similar material on the manifolds .Thanks for the info on this site that helped me trouble shoot and find the solution!

Exh

• Shallow runner
• May 16, 2018

Exh2

• Shallow runner
• May 16, 2018

Pin

• Shallow runner
• May 16, 2018

 

[Shallow runner]

Update

These motors are amazing the boat runs perfect looking at some videos they do not have the typical roller bearing or ball bearings that could potentially be effected by water in the oil that could cause corrosion and bearing spall .It looks like the bearings are more like plates that ride on oil pressure so if caught early and flushed out the bearings are coated with new fresh oil. Obviously if the oil gets to thin it will not lubricate properly especially with the high RPMs . On the first run when I pulled the dipstick there was a very small amount of milky looking oil at the very top of the stick by the cap . This was on both motors it could have been condensation from sitting all winter. 2nd and 3rd time out everything looks perfect no milky residue so if you have some water in the oil or milky oil you may be able to save the motor. I plan on checking the compression again in the middle of the season They were all very similar readings about 185 so what ever water that made it into the cylinder did not seem to have scored the cylinder or damage the piston rings based on the readings.

 

[Duby]

I bought the engine from SBT in clearwater, they are the only one i know that sell these motors remanufactured. I have the non HO it cost me 1800 plus 800 to have yamaha put it in for me and hook it all back up

I ran into the same problem but my corrosion was on #3 on the cylinder block side. I am going with your process of changing the engine out or I might just have the cylinder head replaced. I live in Jacksoville FL did you have the Yamaha dealer in Daytona do the work or in Clearwater were you bought the engine?