# Yamaha 90 2 Stroke Water Pressure



## rkmurphy

Hey all. I have a 2001 Yami 90 2 stroke that has been an absolute beast. Love this motor!

I had my water pump done professionally a couple years back and, recently, the water pressure started to dwindle eventually making its way to sub 10 psi. So, I went ahead and bought a rebuild kit and just did it myself (that dad gom impeller key is impossible to get out, btw!  ). I also tested the thermostat in some boiling water and it opened up just fine. Replaced the gasket and popped it back in.

Anyhow, I took the boat out last weekend and the water pressure still is around 10 psi. The overhead alarm isn't going off or anything, but I've had higher pressure before. Any thoughts?


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## Brett

Hey RK, been awhile. Sounds like you just replaced the soft components
not the housing or base plate. Might be a small loss of pressure there
due to loose fit. Also could be corrosion buildup, or debris in the passage ways
through the block leading to the tee that feeds the gauge. Or, maybe
a poppet valve that has stuck or worn so that less pressure is needed
before the poppet activates.


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## rkmurphy

> Hey RK, been awhile. Sounds like you just replaced the soft components
> not the housing or base plate. Might be a small loss of pressure there
> due to loose fit. Also could be corrosion buildup, or debris in the passage ways
> through the block leading to the tee that feeds the gauge. Or, maybe
> a poppet valve that has stuck or worn so that less pressure is needed
> before the poppet activates.


The only hard component that was replace was the metal insert within the casing. I cleaned up all of the gasket mating surfaces and the base plate really well...so I don't think that's it. Where would this tee be that you speak of? That might be my next place to check. Also, where would I find the poppet valve? I could check that, too.

Good to hear from you again, Brett. It sure has been a while. I'm relapsing my fishing addiction...hopefully this time I never recover!


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## Brett

Yamaha doesn't call it a poppet valve,
their nomenclature makes it a pressure control valve, part # 40

http://www.boats.net/parts/search/Yamaha/Outboard/2001/90TLRZ/CYLINDER%20CRANKCASE/parts.html#

The associated grommets that go with it wear out too.


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## DuckNut

Is the stream weak or just the gauge?

Welcome back Murphy.


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## rkmurphy

> Is the stream weak or just the gauge?
> 
> Welcome back Murphy.


Hey there! The stream seems a little weaker than it should be. I mean...it still pees...but after I took it to Alafia Marine when I had it done professionally, it was like Mr. Ed.

Brett, I did look at that diagram after I read your initial response...love that site! Good prices on parts, too. Is there anything specific I should be looking for with that valve or the spring? I noticed it when I checked the thermostat and it wasn't stuck or anything. I cleaned out the hole and all of the areas with a dremel and very light wire brush.

Thanks for helping me with this guys...hopefully it's just something stupid that I can easily take care of without spending a bunch of money!


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## DuckNut

Had a similar issue years ago. At the top of the intake tube there is a rubber grommet where it attaches to the head. Corrosion gets benind this and grows until it squeezes it closed.

This was found by tearing the motor apart and then cleaning. I now fill a bucket with water and put the lower unit in it and mix in some CLR and run it for a while. Then I do it again with salt away and has been trouble free for 10 years.

I looked n the pictures that Brett linked but can't seem to find the intake tube.


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## rkmurphy

> Had a similar issue years ago.  At the top of the intake tube there is a rubber grommet where it attaches to the head.  Corrosion gets benind this and grows until it squeezes it closed.
> 
> This was found by tearing the motor apart and then cleaning.  I now fill a bucket with water and put the lower unit in it and mix in some CLR and run it for a while.  Then I do it again with salt away and has been trouble free for 10 years.
> 
> I looked n the pictures that Brett linked but can't seem to find the intake tube.


I love the CLR idea. Brilliant! I'll have to try that. Maybe even today! About what ratio to water did you mix the CLR in? Will this affect my seals or gaskets? And is the Salt Away completely necessary? If so, where can I find it?

I'm looking for a way to avoid tearing the motor apart...been there done that with my old Merc.


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## twitch

Where is the water pressure gauge getting its feed from?

Is it T 'eed into the the pisser tube or is it fed through the water jacket?


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## Brett

DN, the intake tube is part of one of the lower unit parts lists
along with the water pump and gearbox diagrams.

RK, anytime a spring or neoprene seal is involved, time and salt/corrosion deposits
cause the springs to weaken and seals to split or distort allowing pressure leaks.


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## DuckNut

RK,
I just bought one of the roughly 10-12 gallon buckets from Lowes - the ones a keg fits in - put the lower unit in fill it up and dump the jug of CLR in. 

Hook a hose up to the pee tube and put it back in the bucket. Keep in mind the water will get hot when it is idling. Don't let it get too hot.

I use one jug of CLR then again with same amount of Salt Away. I can not say if the Salt Away does anything more than doing it again with clean water to ensure it is rinsed.

After this episode cost me several hundred I have been doing it at least twice a year depending how much it is in salt water and 10 years later all gaskets and seal still working. Just make sure you do it once with clean water to make sure it is rinsed.


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## rkmurphy

> RK,
> I just bought one of the roughly 10-12 gallon buckets from Lowes - the ones a keg fits in - put the lower unit in fill it up and dump the jug of CLR in.
> 
> Hook a hose up to the pee tube and put it back in the bucket.  Keep in mind the water will get hot when it is idling.  Don't let it get too hot.
> 
> I use one jug of CLR then again with same amount of Salt Away.  I can not say if the Salt Away does anything more than doing it again with clean water to ensure it is rinsed.
> 
> After this episode cost me several hundred I have been doing it at least twice a year depending how much it is in salt water and 10 years later all gaskets and seal still working.  Just make sure you do it once with clean water to make sure it is rinsed.


Okay so here's what I did...

My Yami has one of those silent flushing attachments that lets you flush it without the motor running. So, I poured some CLR in the faucet end of the hose, turned it on for a few seconds, and let it sit for a few minutes. Then I put some dish soap in the faucet end of the hose and followed the same procedure. I did this twice then did the silent flush with straight fresh water for about 20 minutes, then backflushed through the pee tube. I'll let you know if this has any effect tomorrow. If it doesn't do much, I'll give your method a shot.

As far as the pressure tube, it connects to the head. No tee joint or anything that I can see. Either way, the stream is what seems a bit weaker, not just the pressure read.

Brett, the PCV seemed fine when I checked the thermostat. It's definitely not worn or weak.

Gotta love this stuff!


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## Snookdaddy

I'm 100% sold on the "silent flush" method or any flush method that doesn't require the engine to be running.

Here's my question: How does the thermostat fully open if you're running room temp water out of a hose into the outboard? 

It is my understanding that the cylinder head doesn't get much water until the the temperature rises enough to open the thermostat.. How will this system flush major salt deposits in the cooling passages surrounding the cylinders if the thermostat does not open? 

I'm not a marine mechanic, but I'd really like to know if the outboard gets completely flushed without the motor running.


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## cutrunner

> I'm not a marine mechanic, but I'd really like to know if the outboard gets completely flushed without the motor running.


Your answer,
It doesent

You are correct, for a complete flush it needs to run onthe hose to get to full operating temp to openthe thermostat.


Rc: right before you replaced the waterpump was it pumping stonger than it is now, after you replaced it?

Did you use a Yamaha impeller or aftermarket?

We'll start there


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## rkmurphy

> I'm not a marine mechanic, but I'd really like to know if the outboard gets completely flushed without the motor running.
> 
> 
> 
> Your answer,
> It doesent
> 
> You are correct, for a complete flush it needs to run onthe hose to get to full operating temp to openthe thermostat.
> 
> 
> Rc: right before you replaced the waterpump was it pumping stonger than it is now, after you replaced it?
> 
> Did you use a Yamaha impeller or aftermarket?
> 
> We'll start there
Click to expand...

#1 I ALWAYS run on the hose AND silent flush. If I only do one, I run on the hose to flush it.

I took the boat out Monday morning and the stream looks solid coming out of the pee hole. Now I'm starting to think it might just be the gauge...

I'm going to attempt the CLR in the bucket thing at some point over the next month or so and see what happens, too.

Keep the suggestions coming guys. You are a huge help, as always!


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## JimL

Mine had the exact same issue. Replaced the water pump, poppet, spring, thermo and the alarm still screamed at 4500 rpm and shut her down. CLR or whatever is a waste of time and money. You need to get a yamaha guy to clean the water jackets in the engine. CLR will never remove the deposits that have built up over the years. This is a very common problem with the 90hp Yami.. I spent $275 to have mine done and he replaced the thermo to boot.. Ran perfect at all rpm's after that.. Pay now, or pay again later..


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## rkmurphy

> Mine had the exact same issue. Replaced the water pump, poppet, spring, thermo and the alarm still screamed at 4500 rpm and shut her down. CLR or whatever is a waste of time and money. You need to get a yamaha guy to clean the water jackets in the engine. CLR will never remove the deposits that have built up over the years. This is a very common problem with the 90hp Yami.. I spent $275 to have mine done and he replaced the thermo to boot.. Ran perfect at all rpm's after that.. Pay now, or pay again later..


I'll have to price that out. Water pressure seems fine especially at higher RPMs. And alarm doesn't come on. If it does, it's usually because a bunch of grass kicked up on my LU and blocked the intake. Either way, I'd rather make sure it's tip top shape. May be something to use some Christmas money on. Until then, it's running, running great (for now), and gets me to my favorite spots. Hopefully no issues for a while! I'll keep you all posted. Keep your thoughts and experiences coming! Thanks guys!


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## rkmurphy

> Mine had the exact same issue. Replaced the water pump, poppet, spring, thermo and the alarm still screamed at 4500 rpm and shut her down. CLR or whatever is a waste of time and money. You need to get a yamaha guy to clean the water jackets in the engine. CLR will never remove the deposits that have built up over the years. This is a very common problem with the 90hp Yami.. I spent $275 to have mine done and he replaced the thermo to boot.. Ran perfect at all rpm's after that.. Pay now, or pay again later..
> 
> 
> 
> I'll have to price that out. Water pressure seems fine especially at higher RPMs. And alarm doesn't come on. If it does, it's usually because a bunch of grass kicked up on my LU and blocked the intake. Either way, I'd rather make sure it's tip top shape. May be something to use some Christmas money on. Until then, it's running, running great (for now), and gets me to my favorite spots. Hopefully no issues for a while! I'll keep you all posted. Keep your thoughts and experiences coming! Thanks guys!
Click to expand...

So I went and got a price only to be told by one place that they had done similar jobs before and the labor costs would probably not be worth it. Another place (my main source for trusted motor work) priced me at about $350-$400. He said he is willing to take care of it but suggested I try something else first. The name of the product is Hammerhead Marine Descaler by Bright Bay Products. It's a biodegradable product that is safe for aluminum and attacks calcium and rust in outboard and inboard motors. Apparently it was originally developed for AC systems. They sell commercial systems to outboard repair shops and there are a couple in my area who were asking $250 for the service.

So, since I could get it manually cleaned out for $350 or so, I decided I would take matters into my own hands. I built my own little system with a submersible pump from harbor freight and the Descaler product is only $40. So for around $70 total, I figure I don't have a ton to lose. I'm waiting to receive the product in the mail and will keep you all posted with the progress. Hopefully this works and is a good option for some of you on this forum who may run into a similar problem or just want to prevent such a problem. I've seen a video of this stuff dissolving shells so I think it may at least help a bit. I've also heard some 3rd party testimonials that this stuff is legit and made a night and day difference.


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## cutrunner

If i may, i would like to kinda "slow your roll".
I believe i may know what your problem is, hopefully.
Every 90 2 stroke i have ever ran (thousands..) when hooked up to the silent flush, with the hose turned on(motor not running), peed, just as hard as when it was running.
If i remember correctly you say you are getting good water pressure on the guage, and you arent throwing any alarm buzzers?

Have you tried disconnecting the pee hose from the little plastic nipple in the pan and pulling the other end off as well that connects to the barb on the exhaust cover?

You could very well just have a tiny shell or mud dobber halfway clogging up the hose or plastic pee hole nipple insert in the pan. It happens ALL the time.
If you havent tried that yet, please do!
Remember, if your motor truly isnt overheating and your buzzer is properly working, your not overheating. Its only a tell tale so dont let it snowball into something bigger.
Let me know if that works for you


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## rkmurphy

> If i may, i would like to kinda "slow your roll".
> I believe i may know what your problem is, hopefully.
> Every 90 2 stroke i have ever ran (thousands..) when hooked up to the silent flush, with the hose turned on(motor not running), peed, just as hard as when it was running.
> If i remember correctly you say you are getting good water pressure on the guage, and you arent throwing any alarm buzzers?
> 
> Have you tried disconnecting the pee hose from the little plastic nipple in the pan and pulling the other end off as well that connects to the barb on the exhaust cover?
> 
> You could very well just have a tiny shell or mud dobber halfway clogging up the hose or plastic pee hole nipple insert in the pan. It happens ALL the time.
> If you havent tried that yet, please do!
> Remember, if your motor truly isnt overheating and your buzzer is properly working, your not overheating. Its only a tell tale so dont let it snowball into something bigger.
> Let me know if that works for you


Haha yes sir this is the first thing I checked, honestly. I disconnected it and ran some 80lb test through it to clear anything out that may be in there. I wanted to get rid of the simple solutions before moving forward with anything. Thanks for looking out, though


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## cutrunner

Thats good. Something just still doesnt sit right with me.
Has a service ever been put off to the point of an impeller losing a blade?

When the silent flush is hooked up, theres only a few cavities its flowing thru. Its essentially flowing in , making a loop and back out. No matter what, even if the lower unit wasnt on the motor it should still pee hard on the silent flush (motor not running obviously).

If your chemical flush doesnt work, and you have any mechanical inclination at all, i will work you thru the process of fixing it if you like.
For now im thinking of what else it could be.


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## jms

those older 2 strokes - the 90's,115's and the 130's

there's a seal under the water pump - looks like a top hat , this seal tends to devulcanize,when it does,it areates the water flow,at higher rpms - throwing the alarm on -slow down alarm's off...

in 20yrs,i've never seen an engine suffering from clogged water jackets - not saying it can't happen,never seen it...


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## Creek Runner

> those older 2 strokes - the 90's,115's and the 130's
> 
> there's a seal under the water pump - looks like a top hat , this seal tends to devulcanize,when it does,it areates the water flow,at higher rpms - throwing the alarm on -slow down alarm's off...
> 
> in 20yrs,i've never seen an engine suffering from clogged water jackets - not saying it can't happen,never seen it...



Oh I have, lots of times maybe it's the difference in where we live but I have all manufactures suffer from it. When flushing isn't done properly.

However usually you can tell by seeing how much corrosion is built up on the head and exhaust gasket (outside don't have to remove anything). Also that 90 has a access to the thermostat, if you inspect there 1st and all looks clean then I'm betting it's not your passage ways. 

You said low water pressure, but you didn't it's running hot right? Or did I miss that somewhere? Have you put a ray tech gun on your engine? Pull the thermostat out and put it in boiling water and make sure it's opening all the way, just because it's new doesn't means it's not broke.


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## cutrunner

Lol if the bead blast machine at my shop could talk...
All the heads that ive had to clean the water passageways on..

I still get the feeling that everyone is chasing the problem from the wrong direction.
That motor ahould pee hard as hell on the silent flush with the motor not running. And when it is running it pees the exact same. Leading me to believe there is no problem with a thermostat or water pump, especially since its not throwing an alarm.


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## Creek Runner

> Lol if the bead blast machine at my shop could talk...
> All the heads that ive had to clean the water passageways on..
> 
> I still get the feeling that everyone is chasing the problem from the wrong direction.
> That motor ahould pee hard as hell on the silent flush with the motor not running. And when it is running it pees the exact same. Leading me to believe there is no problem with a thermostat or water pump, especially since its not throwing an alarm.



Not if you got bad water pressure.

I have to admit I didn't read all the post, just the title and the last 2 or 3. 

Here is an idea get a video of the motor on Silent flush and one with it on a real flusher running. Let see what kind of pressure you got and go from there.


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## cutrunner

> Lol if the bead blast machine at my shop could talk...
> All the heads that ive had to clean the water passageways on..
> 
> I still get the feeling that everyone is chasing the problem from the wrong direction.
> That motor ahould pee hard as hell on the silent flush with the motor not running. And when it is running it pees the exact same. Leading me to believe there is no problem with a thermostat or water pump, especially since its not throwing an alarm.
> 
> 
> 
> 
> Not if you got bad water pressure.
> 
> I have to admit I didn't read all the post, just the title and the last 2 or 3.
> 
> Here is an idea get a video of the motor on Silent flush and one with it on a real flusher running. Let see what kind of pressure you got and go from there.
Click to expand...

He said it used to pee hard, and im assuming that was on his house hose, and im assuming that has stayed constant.

Yea, show us a video!! And pictures


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## bermuda

I just had this very same issue with my 2 stroke yamaha 90 - mechanic opened it up and cleaned the water jackets and exhaust area of all the salt corrosion - it was clogged up big time.


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## rkmurphy

Hey all. It has been a while, I know. Finally got some updates on this situation. Unfortunately, it's not good.

I tried the Bright Bay service and it didn't work. So I finally got sick of it and removed the head cover and exhaust cover. First of, it was completely covered in corrosion and grime. Gross. It'll take some work to clean up.

Even worse, the bottom cylinder as well as the walls are corroded. The other 2 cylinders look clean. Any ideas on what the issue could be or what my next step is? My theory is water intrusion but not sure how.  This sucks...I was hoping it was going to be something simple but all I'm seeing is dollar signs $$$

Edit: Added some pictures below





















The only thing that looks out of the ordinary to me (other than the disgusting rust) is the last picture...the head cover gasket had a break in it that developed into a hole, from what it looks like.

Let me know your thoughts!

Edit (again): I also need to add that I have had the boat out a lot recently and it has run great (minus water pressure issue) UNTIL yesterday. Toward the end of the day, it started to hesitate. I gave it some throttle and it caught up...seemed to run fine up until we got back to the ramp. Even then it was idling funny.


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## cutrunner

Clean the water jackets on the heads, clean the gasket surfaces, new gaskets put it back together done.
Minus the retorque later on


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## rkmurphy

> Clean the water jackets on the heads, clean the gasket surfaces, new gaskets put it back together done.
> Minus the retorque later on


What about the water in the cylinder and the corrosion on the cylinder wall and piston?


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## anytide

is that a steam engine murph.......


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## DuckNut

The new gaskets should stop the water. Use your spray and wipe the best you can and coat with oil while you put it back together.


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## Creek Runner

Get the water out of the motor by turning it over by hand while spraying fogging oil into the bottom cyc. This will stop the rusting and keep things lubed until you get it running again. 

Do what cut said clean the corrosion out, use a flat file and lightly file the head, exhaust plate, and block area install new gasket and go fish! Pretty sure your water was coming from a blown head gasket. 

Just for others and your self, the area around the bottom cyc is the worse because that's where the water settles. Also from now on allow more flushing time of fresh water after salt water use.


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## Creek Runner

> The new gaskets should stop the water.  Use your spray and wipe the best you can and coat with oil while you put it back together.


You beat me to it Mr. Duck


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## rkmurphy

Not sure if you can tell from the pictures but the bottom cylinder is the only one with any corrosion. The rest are squeaky clean.

Also, are you sure it's the head gasket? The head COVER gasket was the one with a hole in it but, from my limited research, that gasket plays no role in preventing water intrusion into the motor. The actual head gasket looks perfectly fine.

Trust me when I tell you that this motor gets meticulously flushed after every use...for at least 5-10 minutes. Prior owner(s) may not have been so kind to it, from what it looks like.


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## Creek Runner

> Not sure if you can tell from the pictures but the bottom cylinder is the only one with any corrosion. The rest are squeaky clean.
> 
> Also, are you sure it's the head gasket? The head COVER gasket was the one with a hole in it but, from my limited research, that gasket plays no role in preventing water intrusion into the motor. The actual head gasket looks perfectly fine.
> 
> Trust me when I tell you that this motor gets meticulously flushed after every use...for at least 5-10 minutes. Prior owner(s) may not have been so kind to it, from what it looks like.


No I’m not 100% sure, as I’m not able to see it in person. However by the pics you have provided, that’s where it appears the water is coming from.  The water in the cyc, can only come from 4 places, Head gasket, exhaust gasket, base gasket, or a cracked block. 

Since the motor is already apart and the gaskets are fairly inexpensive I would do the steps I/Cut/Duck provided above, (make sure you use a flat file, to provide a good clean flat surface for the new gaskets to seat to). I’m pretty confident that this will correct you problem; if it doesn’t then it will either be the base gasket or the worst case scenario a cracked block, but I don’t think it’s a cracked block and about 90% sure it’s a gasket problem. 

As for the flushing of the engine, the damage could have very well already been done by the time you got the motor and it just took time for it create a problem. Also just another tip for you and any others reading the thread, do not rely on the self/no start flushing attachment on the engine. Hook up the rabbit ears and run the engine on the hose with fresh water after every use. The flushing attachment just doesn’t do the job correctly, and should only be used during times when running the motor is not an option. Once your done flushing tilt the motor all the way up to allow water to escape from the passage ways and then back down this will help with fresh water build up of scale etc, etc,

Hope this helps!


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## rkmurphy

> Not sure if you can tell from the pictures but the bottom cylinder is the only one with any corrosion. The rest are squeaky clean.
> 
> Also, are you sure it's the head gasket? The head COVER gasket was the one with a hole in it but, from my limited research, that gasket plays no role in preventing water intrusion into the motor. The actual head gasket looks perfectly fine.
> 
> Trust me when I tell you that this motor gets meticulously flushed after every use...for at least 5-10 minutes. Prior owner(s) may not have been so kind to it, from what it looks like.
> 
> 
> 
> No I’m not 100% sure, as I’m not able to see it in person. However by the pics you have provided, that’s where it appears the water is coming from.  The water in the cyc, can only come from 4 places, Head gasket, exhaust gasket, base gasket, or a cracked block.
> 
> Since the motor is already apart and the gaskets are fairly inexpensive I would do the steps I/Cut/Duck provided above, (make sure you use a flat file, to provide a good clean flat surface for the new gaskets to seat to). I’m pretty confident that this will correct you problem; if it doesn’t then it will either be the base gasket or the worst case scenario a cracked block, but I don’t think it’s a cracked block and about 90% sure it’s a gasket problem.
> 
> As for the flushing of the engine, the damage could have very well already been done by the time you got the motor and it just took time for it create a problem. Also just another tip for you and any others reading the thread, do not rely on the self/no start flushing attachment on the engine. Hook up the rabbit ears and run the engine on the hose with fresh water after every use. The flushing attachment just doesn’t do the job correctly, and should only be used during times when running the motor is not an option. Once your done flushing tilt the motor all the way up to allow water to escape from the passage ways and then back down this will help with fresh water build up of scale etc, etc,
> 
> Hope this helps!
Click to expand...

Thanks! I'm pretty sure it's not a cracked block...there's no evidence of that and I feel like I'd see it.

Another thought that came to mind is that I didn't think much of until doing more research. I noticed a small hole in the area circled below on the inner exhaust cover. This would be the area closest to the bottom cylinder. I figured it was supposed to be there. So I spoke to my local Yamaha tech this morning (Jesse at Alafia Marine - stand up guy that I highly recommend)...he said it is absolutely not supposed to be there and that it's likely a corrosion induced hole that he has seen many times before on other outboards. I'm going to look at it more when I get home from work but, that may in fact be my culprit. For a $28 part, I hope that's my only problem.

Obviously I'll still replace all of the gaskets and thoroughly clean all of the surfaces. What do you all think?


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## Creek Runner

> Not sure if you can tell from the pictures but the bottom cylinder is the only one with any corrosion. The rest are squeaky clean.
> 
> Also, are you sure it's the head gasket? The head COVER gasket was the one with a hole in it but, from my limited research, that gasket plays no role in preventing water intrusion into the motor. The actual head gasket looks perfectly fine.
> 
> Trust me when I tell you that this motor gets meticulously flushed after every use...for at least 5-10 minutes. Prior owner(s) may not have been so kind to it, from what it looks like.
> 
> 
> 
> No I’m not 100% sure, as I’m not able to see it in person. However by the pics you have provided, that’s where it appears the water is coming from.  The water in the cyc, can only come from 4 places, Head gasket, exhaust gasket, base gasket, or a cracked block.
> 
> Since the motor is already apart and the gaskets are fairly inexpensive I would do the steps I/Cut/Duck provided above, (make sure you use a flat file, to provide a good clean flat surface for the new gaskets to seat to). I’m pretty confident that this will correct you problem; if it doesn’t then it will either be the base gasket or the worst case scenario a cracked block, but I don’t think it’s a cracked block and about 90% sure it’s a gasket problem.
> 
> As for the flushing of the engine, the damage could have very well already been done by the time you got the motor and it just took time for it create a problem. Also just another tip for you and any others reading the thread, do not rely on the self/no start flushing attachment on the engine. Hook up the rabbit ears and run the engine on the hose with fresh water after every use. The flushing attachment just doesn’t do the job correctly, and should only be used during times when running the motor is not an option. Once your done flushing tilt the motor all the way up to allow water to escape from the passage ways and then back down this will help with fresh water build up of scale etc, etc,
> 
> Hope this helps!
> 
> Click to expand...
> 
> Thanks!  I'm pretty sure it's not a cracked block...there's no evidence of that and I feel like I'd see it.
> 
> Another thought that came to mind is that I didn't think much of until doing more research.  I noticed a small hole in the area circled below on the inner exhaust cover.  This would be the area closest to the bottom cylinder.  I figured it was supposed to be there.  So I spoke to my local Yamaha tech this morning (Jesse at Alafia Marine - stand up guy that I highly recommend)...he said it is absolutely not supposed to be there and that it's likely a corrosion induced hole that he has seen many times before on other outboards.  I'm going to look at it more when I get home from work but, that may in fact be my culprit.  For a $28 part, I hope that's my only problem.
> 
> Obviously I'll still replace all of the gaskets and thoroughly clean all of the surfaces.  What do you all think?
Click to expand...

 I can't see a hole from the pics, but if you scrape away some of the corrosion you should be able to tell if it’s a hole from corrosion or manufacture hole. I can’t remember if that plate has a hole in it or not, I don’t see a purpose it would serve so I would have to agree that’s it’s probably a corrosion induced hole and needs to be replaced.  It is also one of the 4 culprits that I stated in my previous post how water can enter a cylinder.


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## rkmurphy

Took pictures of the hole I'm talking about. See below:


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## Creek Runner

> Took pictures of the hole I'm talking about.  See below:


Yeah 100% sure that's not suppose to be there  , and more than likely the culprit for the water intrusion. R&R exhaust plate and all the gaskets and go fish!!!


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## rkmurphy

Going to order the parts in just a few minutes here. Started cleaning the water passages today. I did the passages around the cylinders first. Wow. Gross. I soaked them with WD-40 and scrubbed away with a wire pipe cleaner. Then, I took my 1500 psi electric pressure washer with the 0 degree tip and blasted away. Left them pretty clean. Soaked everything in WD-40 again, including the insides of the cylinders (figured it would help prevent rust and remove moisture while everything is exposed to the elements of my garage). Will keep you all posted.


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## rkmurphy

Parts are ordered. Getting these exhaust cover gaskets off is a nightmare. I've been slowly working at them with a rotary and a small grinding stone tip. It's brutal on the surface but it's getting the job done...any "minor inconsistencies" in the surface will be filled by the gasket but I just wish there was a better way. Any tips for the future?

Also, thoughts on gasket sealer for the exhaust covers? If you support it, what's the go-to brand?


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## Creek Runner

> Parts are ordered. Getting these exhaust cover gaskets off is a nightmare. I've been slowly working at them with a rotary and a small grinding stone tip. It's brutal on the surface but it's getting the job done...any "minor inconsistencies" in the surface will be filled by the gasket but I just wish there was a better way. Any tips for the future?


Make sure you use a flat file to smooth out the inconsistencies, I use a cordless drill and a wire wheel makes life simple!


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## rkmurphy

> Parts are ordered. Getting these exhaust cover gaskets off is a nightmare. I've been slowly working at them with a rotary and a small grinding stone tip. It's brutal on the surface but it's getting the job done...any "minor inconsistencies" in the surface will be filled by the gasket but I just wish there was a better way. Any tips for the future?
> 
> 
> 
> Make sure you use a flat file to smooth out the inconsistencies, I use a cordless drill and a wire wheel makes life simple!
Click to expand...

I don't think they're inconsistencies like you're thinking. Not like ridges or burs or anything. So a flat file wouldn't really do anything. 

Thoughts on gasket sealer for the exhaust covers? If you support it, what's the go-to brand?


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## rkmurphy

Just an update. Got it all cleaned out and bolted back together with new gaskets. Hooked it up to the silent flush with some Salt Away...had great flow and everything looked perfect until I noticed a small leak out of the bottom of the exhaust cover. Luckily, I had some Permatex Indian Head Gasket Shellac on hand. So, I unbolted the exhaust cover, let the gaskets dry overnight, then applied the Indian Head. Everything's bolted back up and I'm going to let the shellac dry overnight. Hopefully will be all sealed up and ready to run for another 5K hours!


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## DuckNut

Murph - when you get it all good again you gonna take me on that fishing trip that is three years over due? 

I don't really want to paddle...


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## rkmurphy

> Murph - when you get it all good again you gonna take me on that fishing trip that is three years over due?
> 
> I don't really want to paddle...


I'm working on that. There's still a leak. I took the exhaust cover gasket off for the 3rd time now and the Indian Head just caused the gasket to rip. So now I need to find a dealer with the gasket in stock before July 4th. I'm going to try some of this Right Stuff gasket maker to seal the imperfections once I get a hold of a new gasket. The Indian Head wouldn't fill any of the voids but I'm not exactly surprised...guess I was just hopeful. This project is now to the point of frustrating and I want it to be done.


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## anytide

good job murph
[smiley=1-beer-german.gif]


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## rkmurphy

So after must frustration, I think I may finally have it. Permatex's The Right Stuff is an amazing product. I ended up doing 2 things: 1- JB Weld and wax paper to create a "smooth" gasket mating surface where there were imperfections and 2- The Right Stuff between the gasket and the powerhead.

A VERY slight drip remained so I added some more Right Stuff to the edge of the assembled product. It seemed to do the trick. I believe there is still a slight drip but I'm sure it will plug itself over time. It in no way affects pressure or wets any of the engine components. Also, no exhaust gas is leaking out. Put an hour or 2 on it this weekend and it ran beautifully. 15+ psi all day, no overheating...couldn't be happier. Hopefully I can get another couple thousand hours out of her!


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