Really weird issue need help. Engines overheating randomly Yamaha/Dealer says it’s not happening

[Evil Sports]

Get it so the boat runs well and Trade that thing fast.

 

[NewBoater]

Get it so the boat runs well and Trade that thing fast.

What makes you say that? Am I looking at long-term problems where the boat will never run good?

 

[Evil Sports]

Im no expert on motor teardowns but if that material has built up there like that Im wondering where else is it piled up. Some more experienced wrenches here will have to comment. For me, knowing that was there I would always be thinking about it but then again Im a bit of a loon about stuff like that.

 

[swatski]

What makes you say that? Am I looking at long-term problems where the boat will never run good?

Are these MR-1 or TR-1 motors? pardon my ignorance please!

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[Scottintexas]

While I understand and respect Dr. Evil's opinion I don't necessarily agree with it.

are you not going to change something in your flush procedures? are you always going to have a boogie man waiting to throw an overheat light and ruin your day? If so, then you're better off getting rid of the boat (and jet boats).

If you're willing to change something in your flush procedures and can leave it behind you I don't think you'll have additional issues, how many salt water boaters /pwc's do we have and this isn't a every summer issue,

Yamaha's aren't perfect and this is one of those things you have to be mindful of ( I wonder how much my fresh water boat has sediment as I often run in muddy/very shallow water ( I remember one time my cooling water stream turned mud red ))

If it's something you can accept and know maybe you have to pay a little extra attention to I think you'd be ok,

 

[swatski]

Okay, these are MR-1 engines, not TR-1. I don’t think we know much about TR-1 longevity, there have been reports of cooling issues in algae/seaweed-prone waters, the engines did well in snowmobiles but raw water cooling challenges may be different.

The MR-1s though are solid, that type of exhaust obstruction should not be happening in 3 years or so...
I would think a flushing procedure adjustments may be in order?

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[NewBoater]

I will definitely start using the salt away going forward.

 

[Evil Sports]

As indicated I am not versed enough to know what other areas might be affected in these motors. If the brethren here feel clearing them and detailed flushing should suffice then there you have it.

 

[Cobra Jet Steering LLC]

My take on this is those water jackets would cause consistent issues not occasional ones and the pictures don't even look like they came from the same engines metal looks different in some as opposed to others . That Just jumped out at me so I think a first hand investigation is needed .

 

[Gym]

Not discounting @Cobra Jet Steering LLC opinion. If those are from your boat it looks like a combination of salt & sand. zfo you operate in the shallows or beach your boat with the engines running? If that is sand I don't think any chemical would have helped.

 

[NewBoater]

Here are some more pictures I took with my own phone this morning. We are looking at $4000 or so in repairs. I don’t have any interest in spending this kind of money on a boat that’s only a couple of years old. This is very frustrating. I don’t know if I have a case against Yamaha to try to get them to cover it. I’m still not 100% sure this is causing my problem. I’m assuming every boat that boats in salt water has a little bit of corrosion like this.

 

[Speedling]

Here are some more pictures I took with my own phone this morning. We are looking at $4000 or so in repairs. I don’t have any interest in spending this kind of money on a boat that’s only a couple of years old. This is very frustrating. I don’t know if I have a case against Yamaha to try to get them to cover it. I’m still not 100% sure this is causing my problem. I’m assuming every boat that boats in salt water has a little bit of corrosion like this.

I know i only pulled apart a little of my exhaust and it had some corrosion like that from previous florida owner. I had to physically clean a bunch out and i had my thermostat go out.
Perhaps you can do some work yourself?

 

[NewBoater]

How much are the thermostats and how hard are they to replace?

 

[Scottintexas]

thermostats are cheap and easy to replace,

In my opinion I don't think Yamaha has any liability in this, I think it stinks the dealer is wanting to charge you $4k

I'm really sorry to hear their quote, $4k is a lot of money, Maybe call a jetski shop and see if they are familiar with this problem and could give you a quote,

Time is money and I don't know your situation, it may make sense for you to pay someone or even the dealer to fix this but if this were me I'd be trying to do it myself, also the exhaust pipe #12 has passages that will need to be cleaned, that's why I think Cranky's closed loop flush is a good idea,


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[Scottintexas]

 

[NewBoater]

Would running salt away or dawn dish soap a few times a day for a few weeks through the system flushing help clear any of this out?I told the dealer I’m still not convinced this is the problem. Because when it overheats it does not read to the computer system. It’s like there is just a faulty part saying it is overheating.I don’t think the engine is actually overheating. I’m confused on the parts. I have heard people say thermostat, thermosensor, heat sensor. Which one of these 3 would be the most possible culprit of having a bad part causing this problem?

 

[Beachbummer]

Possibly adding some vinegar or CLR to the routine might help. If it's overheating infrequently I would very much try that before spending 4 grand.

 

[Beachbummer]

Also, infrared thermometer would help determine if anything is really overheating. But with the amount of sediment shown, it would not be surprising that there have been some over heat alarms before.

 

[Scottintexas]

Would running salt away or dawn dish soap a few times a day for a few weeks through the system flushing help clear any of this out?I told the dealer I’m still not convinced this is the problem. Because when it overheats it does not read to the computer system. It’s like there is just a faulty part saying it is overheating.I don’t think the engine is actually overheating. I’m confused on the parts. I have heard people say thermostat, thermosensor, heat sensor. Which one of these 3 would be the most possible culprit of having a bad part causing this problem?

Are you going to do any of this or are you telling the dealer to? I think the dealer may balk at wasting his time flushing, I think Cranky's closed loop flush would be a great thing to try, now that the manifolds are already off it may be worth considering scrubbing or breaking some of that clean rather than putting it all back together to try to flush,

Terminology always causes issues, you do have a thermostat along with analog temp sensor and a temp switch,
on buck's video at 6:08 it shows them, if you try to go any deeper in doing this yourself you also need to get your hands on a service manual. and I also believe there is a sensor on the exhaust pipe, maybe #5??

If it was me I'd be doing cranky's flush but I don't know your time/money/experience factors and there are situations where I could certainly understand somebody paying for them to do it,



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[NewBoater]

I’m going to go at this project myself. Trying to figure out which of the 3 parts might be causing this false overheat. Thermostat, thermosensor, heat sensor. And I will try these flushing things myself. That crankys flush seems pretty intense. I may try Salt away vinegar or clr before going that route. Not saying I won’t do it though as I want the boat to run right. There have been no true overheats that I know of that actually read to the computer. These 5-10 times didn’t even read to the computer which makes me think a part is faulty not the cooling slight blockage causing this problem.