1996 Mercury 150HP pee water ???

[CHEVYRIDAZ]

Hey all!

I recently bought a boat with a 96 Mercury 150HP outboard on it. When i run it or just fire it up in the drive way with the water hose the water from the pee hole is very hot. Hot enough for your hand to only withstand it for a couple seconds. The gauge is not showing overheating nor are any alarms going off. Is this normal or are my gauges and or over heating alarm not working properly? The previous owner showed me receipts for a tune up including new impeller, water pump and lower unit maintenance. Any help would be greatly appreciated.

[cart7t]

You're really not supposed to run any OB, especially a V6 on the muffs long enough for the water to start getting really hot which it will if that's what you're doing. There's a big difference in the amount of water moving through the engine between an engine submerged in water vs having muffs on it. If you run that engine long enough that way, the overheat alarm will eventually kick in. I know that happens on my Yammie or any V6 I've ever owned.

[fishfordollars]

You're really not supposed to run any OB, especially a V6 on the muffs long enough for the water to start getting really hot which it will if that's what you're doing. There's a big difference in the amount of water moving through the engine between an engine submerged in water vs having muffs on it. If you run that engine long enough that way, the overheat alarm will eventually kick in. I know that happens on my Yammie or any V6 I've ever owned.

X2, boy if I ever agreed with a post this is it. More damage has been done to outboards on a muff than most would ever believe. Why would anyone want to even run one in the driveway is a mystery to me. If you just want to make sure it will start, just start it and then turn the key off. Don't run it on the muff.

[CHEVYRIDAZ]

Forgot to mention that it does it in the lake too. No alarms but what if the alarm is not working? Also, the boat sat in storage for about 1 1/2 years too. It is and EFI(electronic fuel injected) motor.

[32251]

How about the thermostat?

[cart7t]

Did you have this motor checked out by a mechanic before you purchased it? 

[fishfordollars]

FYI, don't believe any statements or receipts that are stated or produced when buying an outboard. Get it professionally checked before any money changes hands.

Alarms can be and or disconnected at times.

Anyone can produce a piece of paper.

Just because you have a pee stream, it does not guarantee a working cooling system.

Tons of variables that can cause major damage to a motor. If not done , get it checked out.

While your at it, get the fuel delivery system checked. 

If you have a fuel delivery problem on a 2 stroke then you have an oil delivery problem.

You just cannot be too careful.

Good luck.

[CHEVYRIDAZ]

Well i got the receipt and called the shop and as far as i can see the work was done. Also, an electric fuel pump is listed on the receipt. No thermostats on there though. I called Mercury and they said the motor has 140 degree thermostats on it so the hot water is normal. I don't know what to do now!

[fishfordollars]

Well if it concerns you that much, change out the thermostats with a lower temperature rating, or swap the gauge out to see how they compare. About the only thing that will change the temps (if )everything else is in order. Just remember, what is hot to your hand may not be hot to the motor. You can cool it down too much and do damage as well.

The guys that run the Optimax engines are well aware of an issue referred to as "cold seize".

Your electronics are programed to specific temp settings among other things. When you make one change it usually affects many others

Have you checked to see if one cylinder head is a lot hotter than the other? Could be one side or the other if there really is an overheat issue.

Just get it checked out and then you will know. Too many variables to try for an internet board diagnosis.

[Long Mike]

Jack will attest to the fact that I know absolutely nothing about outboard motors.  However, common sense tells me that any cooling water that runs through an internal combustion engine would exit the engine in a VERY warm state.  I have a Mercury 150 and holding my hand in the pee stream has never entered my mind, because I know that it will be HOT.  I know that my overheat alarm works because I've have experienced it after fishing in salad and slop.  Don't be overly paranoid about your engine and its pee stream.  Go out and enjoy your boat.

[CHEVYRIDAZ]

Maybe i am just looking for something to be wrong. The boat and engine are in MINT condition but it did sit for 2 years! The main reason i was shocked/worried is because my previous Mercury 50HP and 90HP and 115HP motors always had cool pee water. Guess i will run it and go from there.

[GLADES]

Does your boat have a water temperature gauge and water PSI gauge? If it doesnt, get them installed. Do not wait for a alarm to tell you something is wrong. If you over trim your motor, you can lose water pressure.

[CHEVYRIDAZ]

Yeah it has both and neither is indicating any issues. I will probably swap out thermos with new ones and take it out for a test drive. My local marine shop has nothing but @$$ #@*^@ working there! They never give a straight answer and are very rude. Plus i don't have the $115 per hour charge they want!

[CHEVYRIDAZ]

Another suggestion i got was the poppet valve? Anyone know where i can get instructions on how to replace this myself?

[fishfordollars]

It's round

Located low on the drivers side of motor

Pull the cover and clean it.

It is nothing more than a bypass. At times the thermostats cannot cool an engine when opened completely.  The poppet valve allows additional water circulation to aide in cooling.

The poppet seats have been known to float out of the block. Check to make sure this has not happened.

[flechero]

Like said above...  hot to your hand and hot to a motor are very different.

If it eases your mind at all, my 1994 merc 175 does as you describe... and has since the day I took it home, brand spanking new.  At idle, the stream gets hot and fairly weak.  When you are underway, it gets stronger.  At full throttle if you look back, it's very strong.

All the older mercs I have been around are similar in that regard.

[jenga]

the first thing I would do is have the oil injection turned off and mix your own oil.  I just had my 200 merc sieze up because of the tube though which the oil runs though break.  Now it is costing me almost 6k to fix. 

jenga

[CHEVYRIDAZ]

Like said above... hot to your hand and hot to a motor are very different.

If it eases your mind at all, my 1994 merc 175 does as you describe... and has since the day I took it home, brand spanking new. At idle, the stream gets hot and fairly weak. When you are underway, it gets stronger. At full throttle if you look back, it's very strong.

All the older mercs I have been around are similar in that regard.

Thanks flechero, it does put me a little at ease. I am getting new thermos tomorrow and will go from there. jenga, my oil injection system seems to be working fine. I would hate to remove it if it is. Is this a common problem or what?

[CHEVYRIDAZ]

Okay, i removed the thermos and they look pretty corroded! I stuck them in hot water and they opened up fine though? Also, there is no seals/gaskets for the thermostats, is this right? I though all thermostat assemblies had to have a gasket/seal. A marine shop told me that there computer was not showing that motor to have seals but i didn't believe them.

[jenga]

Mine was working fine as well.  A few weeks ago I asked that same question on this web site and I had a bunch of people tell me to have it disabled but it was to late it already siezed up.  I now have to have a reman powerhead assembly put in.  I told my mechanic that I will mix my own gas from now on and I won't have that problem.  It takes more time but so what better then having to go through this again.  trust me disinable the oil injection ask anyone.

Jenga

[CHEVYRIDAZ]

Mine was working fine as well. A few weeks ago I asked that same question on this web site and I had a bunch of people tell me to have it disabled but it was to late it already siezed up. I now have to have a reman powerhead assembly put in. I told my mechanic that I will mix my own gas from now on and I won't have that problem. It takes more time but so what better then having to go through this again. trust me disinable the oil injection ask anyone.

Jenga

I have heard a lot of horror stories on the oil injection! What all is required to eliminate it?

[Glenn]

Well hold on a minute there partner.  If it ain't broke, don't fix it.

Water coming out of the peehole should be warm, if not hot.  So long as the water temp gauge looks good, you're good to go.

It should be a strong stream.  If not, replace the impeller (and inspect the housing while you're at it, you might need to replace that too).  That said, water pressure should be your main concern.  Low pressure = higher temps.  It should be at least 15 psi.  I ALWAYS replace the impeller ever 2 years as a standard maintenance precedure, even if the psi is well above 15.

As for oil injection - you said your motor is a '96, right?  If it was going to have any injection issues, it would have had it by now.  If it's working fine for you, then don't mess with it. You could be opening up a bevvy of problems by switching now.

From what you've said, it sounds like the engine is in good condition.  Do the normal maintenance work (oil, spark plugs, etc.) and enjoy! 

[CHEVYRIDAZ]

Well hold on a minute there partner. If it ain't broke, don't fix it.

Water coming out of the peehole should be warm, if not hot. So long as the water temp gauge looks good, you're good to go.

It should be a strong stream. If not, replace the impeller (and inspect the housing while you're at it, you might need to replace that too). That said, water pressure should be your main concern. Low pressure = higher temps. It should be at least 15 psi. I ALWAYS replace the impeller ever 2 years as a standard maintenance precedure, even if the psi is well above 15.

As for oil injection - you said your motor is a '96, right? If it was going to have any injection issues, it would have had it by now. If it's working fine for you, then don't mess with it. You could be opening up a bevvy of problems by switching now.

From what you've said, it sounds like the engine is in good condition. Do the normal maintenance work (oil, spark plugs, etc.) and enjoy!

I REALLY want to enjoy it Glenn, just being cautious. The impeller was replaced in Aug and has not really been used since. So were the plugs, fuel/water sep, lower unit oil and now the thermos are in too. But my PSI gauge is showing only 3psi at idle and the stream of pee water is weak to non existing until you run at higher speeds? Could the psi gauge be faulty? Can a bad poppet valve cause all this too? I HATE OUTBOARD MOTORS!!!!

[Glenn]

Yup, a bad poppet valve could cause it. But keep in mind it's going to be around 5psi at idle, so 3 isn't THAT bad.  If it's above 15psi while running on plane, you should be fine.

Example:  My motor had a clogged poppit valve (dang sand dunes!).  Idle psi was ok.  The pee pressure was a little weak, but wasn't too bad.  However it wouldn't go above 10psi, even at WOT.  Clue train!!

Cleaned the valve, and the stream was stronger at idle (@5psi), and it shot up to 24psi at WOT. 

One other thing to check is the hose connections for the pee water.  Just trace the hose back from the hole and make sure they're on nice and tight.  I'd even pull the hose loose and blow through it to make sure it's not obstructed.  Unlikely for sure, but since you're there...

And pull the screen off the intake and take a look inside with a flashlight.  Even stick your finger in there and check for any obstructions.

[CHEVYRIDAZ]

Where is the intake screen located Glenn? Also, do you know of any instructions on replacing the poppet and what all parts are included in the system? I cannot find it on my motor. THANKS A LOT