| Author |
Message |
    
Mike Nutter
New member
Username: mpnutter
Post Number: 3
Registered: 09-2007
| | Posted on Sunday, May 04, 2008 - 10:51 am: | 
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Hello all!
I believe this question has been beat to death but I really need to ask it anyways because I am at my wits end and I think I have done all that I have found here.
I have a 1987 Baretta with an AQ131A.
The boat will run fine in the driveway with muffs on it all day long, as it will cruising.
As soon as I hit plane, the temp rises and overheats.
I have done the following...
Replaced impeller
Replaced thermostat
Replaced intake hose and connector on outboard.
Replaced cracked exhaust hose
Replaced radiator cap
I am not finding any leaks on the inside.
I have the service manual for the model.
Please any ideas would be greatly appreciated of what to look for.
I don't want to have to replace the manifold until I have tried to figure out if it is really needed.
Thanks in advance!
Mike |
Mike
Advanced Member
Username: mike77cj
Post Number: 119
Registered: 06-2007
| | Posted on Sunday, May 04, 2008 - 04:55 pm: |
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How old is your exhaust manifold? If it is over five years and you run in salt water, I would suspect it is scaled, reducing water flow and leading to the engine overheating.
Pull the manifold and see what it looks like.
What rpm band are you planing at? |
El Pescador
Senior Member
Username: el_pescador
Post Number: 3081
Registered: 02-2006
| | Posted on Sunday, May 04, 2008 - 07:54 pm: |
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1) Remove the copper pipe going to the bottom aft of the exhaust manifold and stick a screwdriver or a small rod into the manifold. If it comes out muddy, that's a sign of possible obstruction;
2) Remove the wide hose connecting the exhaust manifold to the exhaust pipe and look at the water passages between the outer an inner part of the manifold: if choked with rust/scale, throw the exhaust manifold away and get a new one.
3) Stick a garden hose at the bottom of the manifold (into the hole where the copper pipe is connected) and flush the manifold with water. See how easily (or difficult) the water flows out of the water passages. That will give you an idea of the manifold's internal condition.
4) Block the water intake grids in the outdrive with duct tape, then remove the suction copper pipe from the raw water pump, stick a garden hose into the copper pipe, pressurize it and look for leaks between the garden hose and the grids: any water leak will pinpoint a source of air ingress.
Hopefully one of the above should do it for you. |
Mike Nutter
Member
Username: mpnutter
Post Number: 4
Registered: 09-2007
| | Posted on Sunday, June 29, 2008 - 11:23 am: |
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All,
Sorry for a the delay in this response. I lost track of this post.
Since the post, I have done the following.
1.) I have stuck a hose in the exhaust pipe and I seem to have good flow.
2.) I have removed the copper insert in the heat exchanger and spray this. Note: This seemed to improve the time it took to overheat.
3.) Someone told me to pull the thermostat to allow more water to enter. Note: I think this overheated worse.
4.) I removed the copper insert in the heat exchanger again and acid dipped it in a hydrocloric acid mixture designed for copper heat exchangers. Note: This removed a lot of scale and I will be testing this later today. |
Drew H
Member
Username: hammerslammer
Post Number: 16
Registered: 05-2008
| | Posted on Tuesday, July 01, 2008 - 07:35 pm: |
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mike i just went through this and trust me when i tell you if that sucks in the least bit of air will over heat try sqeezing the muffs together to force more water in,depending on how many feet your hose is will make a difference,also with out a ? DO NOT RUN THAT WITH OUT A THERMOSTAT,also make sure u have good water flow coming from the back of the boat when your running...... |
Mike Nutter
Member
Username: mpnutter
Post Number: 5
Registered: 09-2007
| | Posted on Wednesday, July 02, 2008 - 11:36 am: |
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Drew, I think you were referring to running this on muffs. I can run on muffs all day long without an overheat. It is only on load in the lake.
I tested the engine after acid dipping the copper insert and saw a lot more time before overheating. After overheating, I put the engine in neutral and ran the engine and it cools down almost instantly.
I had put a clear hose on the intake and see absolutely no air coming into the hose.
I replaced the copper insert today to see if this would help even more if there is a blockage in the unit and will be testing tomorrow night.
Thanks,
Mike |
Eddie F
New member
Username: eddy
Post Number: 1
Registered: 07-2008
| | Posted on Thursday, July 03, 2008 - 09:24 am: |
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You folks have given me some new imformation that may just help me,
I have a 230 2.3 B volvo engine, the freash water pump is leaking from the front seal.
so I ordered a new pump , should be here next week
anyway , when it's running on the muffs the temp never climbs over 145
I put it in the lake last night and ran it as my mechanic said I could do,
The temp gauge went way up to the 200 mark.
Will this new fresh water help to stop this and make it cool so I can run it....I only run this boat 2 maybe 3 times during the summer on the lake, I may run it more this summer due to fuel prices in my cruiser.
great boat for the weekedays , cruiser on the weekends. |
El Pescador
Senior Member
Username: el_pescador
Post Number: 3527
Registered: 02-2006
| | Posted on Thursday, July 03, 2008 - 08:51 pm: |
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The correct operating temperature range for the 230 coolant is 180º-198ºF. |
Eddie F
New member
Username: eddy
Post Number: 2
Registered: 07-2008
| | Posted on Friday, July 04, 2008 - 10:01 am: |
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so then running a high temp would be somewhat normal.
I also remeber I had covered the hole in the bottom of the foot with duct tape when I was running it on the muffs in the driveway.
They might of had something to do with thenhigher temps also...
one mechanic told me also, it may be sucking air when on plane , so once I get the new raw water pump it should make a considerable difference.
Do you agree???? |
El Pescador
Senior Member
Username: el_pescador
Post Number: 3537
Registered: 02-2006
| | Posted on Friday, July 04, 2008 - 09:15 pm: |
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If it sucks air on the plane, then the raw water hose connector in the outdrive is likely corroded/perforated. Do a search in the forum for raw water hose connector, this has been discussed countless times. |
