Port engine milky oil 2006 AR210 MR1

[WREKS]

Duh. On mine, the gasket was good. the fire ring was grooved. https://jetboaters.net/attachments/port-engine-cylinder-1-head-erosion-jpg.101033/

 

[Jon D]

From the time I started tear down on this blown motor to the time I test drove it in the waverunner was right at about a month as I chipped away at things in my spare time. The only question now is whether or not we’re keeping the extra toys lol. I do have a bunch of extra pictures if anybody has any questions about this process.

@CaptRedbeard I just noticed this whole thread for the first time, excellent work and thanks for documenting! Wondering how the motor you fixed is is doing this spring? Do you think there is any connection between the crack in the block and the gasket problem? Several of us with the crack have eventually ended up with water in the oil but you might be the only one who has posted anything about tearing it down so the rest of us don't really know where the water was coming from (assuming crack went through to inside also). It is still bizarre to me that there are several of us with this exact same crack yet it doesn't seem to be a widespread problem and we don't have a clue what might have caused it.

The motor I swapped out last spring was JB welded and is in the donor waverunner. I was surprised to get use out of it all last summer despite it getting a small trace of water in the oil but this spring when I started it up it pretty quickly made the fresh oil milky so I am not even putting it in the water. I'll also note that at one point last summer it started running pretty bad and the oil didn't look bad so I pulled the #3 spark plug and it was all rusty, replaced that and all good again. I enjoyed having the waverunner more than I expected last year so am actually shopping for another one but now this has me wondering if I should crack open the top end of the engine and try to get more life out of what I have. I've done a bit of small 2 stroke engine work but don't have any specialized tools and anything with the valves on these things is out of my realm of knowledge/exposure to. Can you pull the head off while leaving all the valves buttoned up in place? I guess any additional info you could send would be great although I really question it being worth putting any effort into something that will still have a cracked block. Thanks!

 

[scokill]

@CaptRedbeard I just noticed this whole thread for the first time, excellent work and thanks for documenting! Wondering how the motor you fixed is is doing this spring? Do you think there is any connection between the crack in the block and the gasket problem? Several of us with the crack have eventually ended up with water in the oil but you might be the only one who has posted anything about tearing it down so the rest of us don't really know where the water was coming from (assuming crack went through to inside also). It is still bizarre to me that there are several of us with this exact same crack yet it doesn't seem to be a widespread problem and we don't have a clue what might have caused it.

The motor I swapped out last spring was JB welded and is in the donor waverunner. I was surprised to get use out of it all last summer despite it getting a small trace of water in the oil but this spring when I started it up it pretty quickly made the fresh oil milky so I am not even putting it in the water. I'll also note that at one point last summer it started running pretty bad and the oil didn't look bad so I pulled the #3 spark plug and it was all rusty, replaced that and all good again. I enjoyed having the waverunner more than I expected last year so am actually shopping for another one but now this has me wondering if I should crack open the top end of the engine and try to get more life out of what I have. I've done a bit of small 2 stroke engine work but don't have any specialized tools and anything with the valves on these things is out of my realm of knowledge/exposure to. Can you pull the head off while leaving all the valves buttoned up in place? I guess any additional info you could send would be great although I really question it being worth putting any effort into something that will still have a cracked block. Thanks!

I limped along a Toyota Supra for about a year with a cracked head. It performed flawlessly until a single sparkplug would foul. I would change the plug and all was well. I finally sprung for a new head which wasn't cheap. While the head was being replaced the ECU was "stolen" at the dealership and they wanted me to pay $1,600 for a new one. They pointed to their term for the repair that they wouldn't be responsible for stolen items out of the vehicle. I said, wouldn't that just apply to sunglasses, wallets, etc.?? I said what if someone stole the whole engine? My logic was too much for them and they finally gave me the car when repaired, but it was never the same.

 

[kjr6306]

If you are getting water in one cylinder (rusty plug) you more than likely have a bad head gasket or possibly an issue with the corrosion on the exhaust manifold. If you are getting water that fast into the oil you more than likely have a cracked head or block. One thing to note is that the external crack that a lot have had near the water outlet/temp sensor will not cause water to get into the oil. That area is just a water jacket and will cause water to leak into the bilge.... There's really only one way to figure it all out and that's to start tearing down the engine. The head can be pulled without the valves falling out (OH Cams). I would recommend pulling the engine as it will save time in the long run. It's impossible to get anything done with the engine in the boat...

 

[CaptRedbeard]

@CaptRedbeard I just noticed this whole thread for the first time, excellent work and thanks for documenting! Wondering how the motor you fixed is is doing this spring? Do you think there is any connection between the crack in the block and the gasket problem? Several of us with the crack have eventually ended up with water in the oil but you might be the only one who has posted anything about tearing it down so the rest of us don't really know where the water was coming from (assuming crack went through to inside also). It is still bizarre to me that there are several of us with this exact same crack yet it doesn't seem to be a widespread problem and we don't have a clue what might have caused it.

The motor I swapped out last spring was JB welded and is in the donor waverunner. I was surprised to get use out of it all last summer despite it getting a small trace of water in the oil but this spring when I started it up it pretty quickly made the fresh oil milky so I am not even putting it in the water. I'll also note that at one point last summer it started running pretty bad and the oil didn't look bad so I pulled the #3 spark plug and it was all rusty, replaced that and all good again. I enjoyed having the waverunner more than I expected last year so am actually shopping for another one but now this has me wondering if I should crack open the top end of the engine and try to get more life out of what I have. I've done a bit of small 2 stroke engine work but don't have any specialized tools and anything with the valves on these things is out of my realm of knowledge/exposure to. Can you pull the head off while leaving all the valves buttoned up in place? I guess any additional info you could send would be great although I really question it being worth putting any effort into something that will still have a cracked block. Thanks!

I believe I had two separate issues with this motor. One issue was the crack in the block between the outer surface and the water jacket. The other issue, the blown head gasket, is what led me to pulling the engine and tearing it down to find the cracked block. The cracked block would be the source of the mystery water in my bilge after every outing. I can't say for certain whether or not the two issues are related, but they're both in the same area of the block.

I realize I hadn't updated this thread since last fall. On our last outing in the fall I discovered the other engine had the same exact crack in the exterior of the block as this engine documented in this thread. I pulled the motor, JB Welded it just like I did in the documentation in this thread, and reinstalled the motor. I did all this while in the boat, just lifted the motor out of the engine bay on the gantry. This spring, the motor fired up and ran without leaking water while on the hose, but I have not had the boat in the water yet. I hope to have good luck with this motor repair as well, seeing as it's just water pressure in the water jacket and not related to the combustion chamber.

All that said, I have no clue if the cracked block is due to improper maintenance by the previous owner, or a bad casting of the block. The few documentations of this specific crack in the block I believe have all been from 2006 year motors which leads me to believe that it may have been a casting issue.

 

[Jon D]

@CaptRedbeard you might have seen my old posts. I have owned my 2007 sx210 since new (engines manufactured in 2006) so I know nothing bad has happened to my engines other than one very brief overheat alert and I am quite particular about maintenance. It has always been where it freezes in the winter although first crack showed up when it had always been kept in my garage. I even try to push some rv antifreeze through when winterizing even though I rev the engines before and after doing that to blow all the water out. I first noticed the crack in my Starboard engine back in 2017, just water spraying in the engine compartment when on the throttle. I did my best to patch that up with JB Weld without removing the engine (I did okay but maybe could have done better removing it). The JB Weld only held for about a year then it cracked, I just kept on running it with some water getting in bilge every outing. July 2021 I was running across the lake and the RPMs on that engine started jumping around so I stopped and feeling I was running on borrowed time anyway immediately checked the oil to find what looked like chocolate milk shake in the tank. I looked over the port engine good to make sure no apparent issue with that (not sure I would have proceeded knowing both engines would go) and decided to swap a waverunner engine into starboard side - that waverunner was not in the best shape so sold everything for parts. In October 2021 when changing the oil I noticed a very slight sign of water in the port engine oil and saw teeny tiny crack in same spot on outside of that engine, barely noticable water stain so I started to look for another waverunner. Spring of 2022 I found another waverrunner and did a complete swap, jb welding the bad moter before putting it in the waverunner. I ran the waverunner all last summer with only a little bit of water ever getting in the oil, the #3 spark plug went bad at one point. So my first one leaked on the outside for years before water in the oil but the second one seems to start getting water in the oil at same time as the crack started to show. I don't know if I had/have bad head gasket or if the crack does go through on the inside, one of my engines is gone but would be interesting to see if the other one has a head gasket issue but I'm not sure I want to put the effort into it given the crack. I'm always going to wonder if something caused those cracks or if there was a bad batch of motors - one of the waverunner engines I use now is from earlier in 2006.