Yamaha 4 Stroke 9.9 Question

[Ward H]

I saw something on my 2013 Yamaha 4 Stroke T9.9 I hadn't noticed before.
About 1/3rd down on the shaft housing there are 2 embossed holes facing the pivot shaft. They are one along side of the other and look to be about 1/4".

There is water coming out of both embossed holes when the OB is running. It is low pressure but does increase when throttle is increased.
The water flow tater tale is showing a strong flow of water.

I didn't notice this until I was lowered into the water during launch and had let the motor warm up for about 15 minutes. I bought the OB through the marina and the marina owner/yard manager and his OB mechanic both looked at it and said they never noticed one doing this before and did not know if there was a problem. I was able to motor to the slip with no signs of overheating or other problems.

They will check with the marine supply where they got the OB but with this being launch season it will take a few days so I thought I would ask here.

I didn't get a pic but pulled this one off the net and the arrow shows about where these two embossed holes are located.

Anyone have any ideas if this is a problem or not.

 

[svchickadee]

I have a 2012 T9.9XEHA Yamaha. I ran the outboard in the slip today and did not see any water coming out of the engine above the lower unit with the exception of the peahole.

 

[Chief RA]

On my 9.8 Tohatsu I don't notice any water except for pee stream if in the water. Where I notice some water coming out of other small orifices in the lower unit is when attached to the hose. I would call Yamaha about this as I suspect those are over pressure water relief ports.
Please let us know. Chief

 

[Ward H]

Thanks for looking chickadee.

Yep Chief, that was what I was thinking.

I'll be making some phones calls tomorrow. I can't find anything referring to them online.

Thanks

 

[kloudie1]

I think those are drain holes at the lowest point of that casing to which the engine block is attached.. have you run it without the upper cowl to look inside to see where the water is coming from? If one of the 4/6 water tubes is leaking, it would exit there, I think. There are several little rubber tubes, plastic ells, etc that are connected to the cooling water circuit, especially around the head. Ya might want to take the cowl off, start the engine, and carefully look around with a flashlight in the lower part of the upper casing to determine where that water is leaking from.

 

[Brian D]

Do you mean like this?

This is an older motor but I think maybe the holes are the same. I believe it is a pressure relief. Why? I don't know. But I do know when I had my motor serviced it started to do it. I posted on a Yamaha website and someone said it was pressure relief and not to worry. So I didn't.

My new 9.9 dose not have this.

 

[Ward H]

Claude,
We did take the cowling off and couldn't find any leaking hoses or fittings although that would make sense.
Brian,
That is close to what I am seeing if that is on the opposite side of the prop, which it looks to be in that photo.
Hopefully I will get the same answer from the dealer who is closed on Mondays so I may not know until Tues.
We have a vacation planned around sailing for a week in two weeks. Just kind of nervous this could screw up those plans.
OB is under warranty if there is a problem. Just need it fixed quickly.

One other note was that when starting the motor after it sat for a few minutes it took about 30 to 60 seconds before the water came out of these holes.

Fingers crossed it is just a relief valve and working properly.

 

[Brian D]

Ward, my new OB does the same thing when starting. So before I actually get it running, I will crank it a few times (not to start, just crank) until the stream starts. Then I will give the go and full start. This way I know the stream is going.

But even before that, I will connect the flush hose and run water through the engine to make sure nothing is clogged.

Good luck.

added: another though on the pressure relief. I am wondering if there has to be a certain PSI of water in the system to work correctly. I wonder if the whole cooling was designed to exceed that level to make sure the level was achieved. Anything above that level triggers a relief valve and this is what we see. Kind of like a pressure cooker. Just a SWAG.

 

[Picflight]

On a normal engine there should not be any water exiting except the telltale. If it is exiting from pressure relief valves than there is blockage in the system that is pressurizing it.

Look at the service manual of the engine to figure out what those outlets are made to do.

 

[MaxinCalgary]

I have a 2014 T 9.9 .
Two holes facing forward that leak water. Mine does the same. I believe it's the exhaust cooling flow. Mine does the same.

 

[Ward H]

I went down today and took some pics. Since Brian and Max see the same thing on their new OBs and the marina mechanic thinks it is normal I am starting to relax.
I'll be calling the dealer and will report back tomorrow.

 

[Ward H]

And the anser is Yes, it is normal!

I spoke to the dealer this morning.
Yes, the water coming out of these two forward facing ports is overflow due to the water pump pumping more water than can be passed through the cooling system.
It is also normal to see some spitting out of the port at the rear of the OB just under the cowling clamp. This is an exhaust relief valve and since it is a wet exhaust system, it may spit a bit.

He also confirmed that the tell tale water flow is after the cooling system so as long as that flow is strong everything is good.
I wasn't sure about that, just knew if it stopped there was a problem.

Thanks for the help.

 

[kloudie1]

Yamaha 9.9 mystery flow

Interesting! I am intimately involved with an older model (see pic of clearing water jacket) and it does not have the water flow holes.. Makes sense..
Glad ya got the question answered, Ward !

 

[Chief RA]

Good followup Ward! The dealer clarification helped us all be sure about this. Thanks, Chief

 

[Brian D]

Thanks, Ward!

 

[Picflight]

Great job @ward.

 

[Brian D]

Ward, here is a chart showing the path of cooling water in a T9.9 outboard. I knew I had this image somewhere. Just found it in my older Yamaha repair manual for outboards. I am sure the new motors are very close so it should be somewhat the same.

 

[Ward H]

Brian,
Good diagram. And where the overflow holes are is not shown explicitly but does show something there.
Thanks

 

[jimontheboat]

Hi Ward,

Been a few years since this post. My 9.9 Yamaha is doing the same thing- have you needed any service to relieve the pressure, or has the engine been operating fine with water coming from relief holes?

Thanks!

 

[agprice22]

Yup. My 9.9 has the same overflow feature.