225 Running Hot !!! FIXED!!!

jcory

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Aug 7, 2010
Messages
22
Got a 95 Mariner 225 EFI Magnum--Just started running hot. Crashed the boat and replaced the lower unit--Thats when it all began. Replaced Thermos-New water pump-Pulled heads--Doesnt appear to be any blockage anywhere. It used to run about 145 but now runs closer to 165 to 190 temp. Cant get this one figured out--Any ideas out there???

Changed water pump again last night just to be sure. No change--Could I have been sent the wrong lower unit--Water pump not pumping enough water for a motor this size??? Running out of ideas here. Any help would be good.
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Re: 225 Running Hot

Re: 225 Running Hot

First thing I would do is install a water pressure gauge... This will tell you if the problem is in the pump or the powerhead...

Chris..........
 

J Hartman

Petty Officer 3rd Class
Joined
Jul 3, 2010
Messages
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Re: 225 Running Hot

Re: 225 Running Hot

I may be incorrect so do not quote me. But I thought 160 degrees F was proper operating temp?
 

Faztbullet

Supreme Mariner
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Mar 2, 2008
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15,902
Re: 225 Running Hot

Re: 225 Running Hot

I agee with Achris as pressure guage will help greatly, and when you "crashed" boat did you damage hull or just motor?
 

jcory

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Re: 225 Running Hot

Re: 225 Running Hot

There was some damage to the hull but it has all been repaired at this time---When I pull the thermo hose I only get water ever now and then. Sometimes it seems to be pumping enough and the next test run it wont pump anything out the thermos even when they are open. The kicker here is the tell-tale hole alwys has a stream--not very strong but it is there. What pressure should I be geting on the water pressure guage???--
 

achris

More fish than mountain goat
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Re: 225 Running Hot

Re: 225 Running Hot

As the engine speed increases, the water pressure should rise to about 10-12 psi, then drop as the poppet opens.

Had another thought while I was out fishing today.... Since the problem only started since the new gearbox has been on, then it's most likely that the problem IS the gearbox. I'd start by looking to see where the water pump could suck air or exhaust gases.

The only drawings I can see show the old style (high pressure, low volume) pumps. The pumps on the old and new box are the same?

Could you post up the engine serial number?

Thanks,

Chris..........
 

jcory

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Aug 7, 2010
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Re: 225 Running Hot

Re: 225 Running Hot

Serial #OG274975----When we changed lower units i the only difference i noticed was the front end of the torpedo has holes in it---I was told this was the NEW unit for my motor and these holes allowed better water flow--The old unit has already been sent in for a core charge so I cant compare them side by side. I will look and see if there is an air leak anywhere but i cant think of where it could be???
 

Faztbullet

Supreme Mariner
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Mar 2, 2008
Messages
15,902
Re: 225 Running Hot

Re: 225 Running Hot

If you running it on muffs and front holes are not covered it will not pump correctly, its needs to be in a barrel or lake. I think you have damaged the exhaust tube(cracked) or damaged water tube..
 

jcory

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Re: 225 Running Hot

Re: 225 Running Hot

got it in the shop--I will contact them and let them know. Thanks for the info guys i will let you know what we find.
 

achris

More fish than mountain goat
Joined
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27,468
Re: 225 Running Hot

Re: 225 Running Hot

OK... by that serial number you have the new style water pump (Low pressure, high volume) and there are some traps when putting them back together....

The gaskets and the gasket surfaces need to be clean, and flat. The seal on the top of the pump housing needs to be set properly, and that can ONLY be done with the seal installing tool (always included with a new impeller or V-seal). I also like to use the pump housing installation alignment pins too. Also the 2 'O' rings in the water tube coupler need to be checked. And the filler block needs to be in good condition (below the back end of the water pump face plate).

Good luck....

Chris.......
 

milehighboater

Petty Officer 1st Class
Joined
Jul 28, 2009
Messages
235
Re: 225 Running Hot

Re: 225 Running Hot

If you don't mind me asking, what does one have to hit to take a lower unit from a 225 out? In other words what did you run over?
 

jcory

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Aug 7, 2010
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Re: 225 Running Hot

Re: 225 Running Hot

Thanks for the info---I will check on the water pump seals next. The culprit was one of those famous Lake of the Woods under water islands at about 25 MPH--I have a special name for that rock now but it is probably not fit for this forum.
 

jcory

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Re: 225 Running Hot

Re: 225 Running Hot

Chris,
Exactly what O rings are you describing. The couple is a piece of rubber that fits over the top of the water pump--I thought that fit over the water tube going up into the motor.??? As I did not install this lower unit myself at first I did not see any O rings. Does it slide over the tube or just where does it go? The feeling I am getting is that I am losing water somewhere!! Just not getting enough volume to fill the water jackets and make a complete cooling circulation is my thought. Thanks for all the advice and I will keep on trying---
 

achris

More fish than mountain goat
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Re: 225 Running Hot

Re: 225 Running Hot

In the diagram below #40 (x2) are the 'O' rings. If they are missing/damaged then you can lose water volume (that would also show up on a pressure gauge). Also if seal #33 is not installed correctly, then the pump can suck air, as with leaks under gaskets #34, #35 and plate #36...

Do you have a service manual for this engine (factory, not hand wipes by seloc or clymer)?

Chris........

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jcory

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Re: 225 Running Hot

Re: 225 Running Hot

I do not have a manual but looking at the diagrem you sent my pump WAS NOT installed correctly---I will remedy that and see what happens. There was only 1 gasket placed and no O rings---And if i am looking at it right the one round O ring looking thing should be installed through the pump housing not just sitting on top of it---
 

jcory

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Re: 225 Running Hot

Re: 225 Running Hot

The O ing looking thing is the seal---should that be installed into the housing where the shaft slides over it and not just sitting on top of the housing??? and do both O rings sit on the bottom of the couple or does 1 go on bottom and 1 on top??? Man you are a wealth of info and thank you so much for putting your time into my problem.
 

achris

More fish than mountain goat
Joined
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Messages
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Re: 225 Running Hot

Re: 225 Running Hot

The O ing looking thing is the seal

#33?

jcory said:
---should that be installed into the housing where the shaft slides over it and not just sitting on top of the housing???

It's install on the top of the housing and MUST be done with the tool

jcory said:
and do both O rings sit on the bottom of the couple or does 1 go on bottom and 1 on top???

Both 'o' rings go in the grooves inside the coupler. The use of the alignment pins when putting the pump housing on is VERY important. If you have a misalignment of the housing, the engine can overheat....

jcory said:
Man you are a wealth of info and thank you so much for putting your time into my problem.

My pleasure....

Download a manual for your engine HERE. The password for the file is <ribforum> and I use 7-zip to decompress the file... You'll find all the details about assembling the pump in the last couple of pages of the lower unit section....

Chris...........
 

jcory

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Aug 7, 2010
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Re: 225 Running Hot

Re: 225 Running Hot

OK--Mechanic is saying that it is either the grommet where the water tube goes through or a gasket up on the top end---Waiting for parts to come in--Will let you know---Man what a pain in the rear---Canada trip 28 days away and here i sit waiting---Getting down to the nitty gritty
 

naveall43

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Aug 9, 2010
Messages
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Re: 225 Running Hot

Re: 225 Running Hot

I am not sure if I am in the right place or not,

i have a 1980 Sea Ray 225 with a chev 350 with a 260 on the engine, this past week end while backing out of a very tight dock, i ran into a mud mound that i did not see unitl i had the boat back there and the depth finder said i was in 1.5 feet of water, so the whole lower end of the engine hit this mess, plus i had the prop completely entangled in sea weed, which i lifted the transum back out and cleaned off,

up to this point i have never had a over heating issue, i could run the engine at 1/2 wide open, flying through the water and barely got about 1/2 on the temp gauge, and i do watch all these guages everytime i am out,

my question is did i suck a bunch of sea weed or mud into the lower intake and if i did, how do i clean all this out, i took the little covers off the intake on the lower end and since i was told there was a screen on the intakes i though i would just clean this out, needless to say there was nothing there, i am looking for a manual for this engine to help me,

i have read everything from hooking the lower end to a source and letting it run to taking off or opening the side ports to let water flow through in the even there is mud or something impeding the lower end from proper water intake,

i know this is a bone head mistake, since i have made this same route backing out of this dock many times, i was not thinking i would have many problems, i did lift the lower unit up going back in to recover the boat to go home, we did spend the whole day fishing, i did not notice at the time any problems, the engine does start and run like it always has, excpet now it heats up after about 7 pr 8 minutes of running at open throttle,

thank you for all your ideas,

al
 

jcory

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Joined
Aug 7, 2010
Messages
22
Re: 225 Running Hot

Re: 225 Running Hot

Both gaskets blown up on top end---Got it togethr tonight and taking it to lake in the morning---Wish me luck--God knows I need it--
 
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