AQ131a & Penta 275 Missing Cooling system ?? 1987 Bayliner Capri

axisg

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May 22, 2013
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My First Post ! I have been trolling the forums for the last week or so trying to familiarize myself with my latest money-pit ! I picked up an 87 Bayliner Capri with the VP 2.3 AQ131a & 275 Sterndrive. We have put about 6 hrs of time on the lake with this machine and it has performed quite well. I bought it from an older gentleman who has had the boat for the last 20 years. When selling the boat he had briefly explained to me about the fresh-water cooling system and how this way the motor would run cool. Made sense to me and it didnt raise any "red" flags at the time.

Now over the last week I have downloaded the Workshop Manual, VP Sales Brochure, and the VP Operators Manual. In all the pics I see of this motor, there is always a red coolant tank mounted to the front of the engine. However in this boat there is a hose connected from the Thermostat , thru a reducer to 3/4" and it routes into the opposite side of the block. And another hose from the water pump, thru a reducer to 3/4" and back into the opposite side of the block. Is this actually a "safe" way to operate the boat ?

See a couple pics below. I suspect there is actually no thermostat in the housing. When we had the boat out last time the temp guage never moved

IMG_1438.jpgIMG_1437.jpg
 

Don S

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Re: AQ131a & Penta 275 Missing Cooling system ?? 1987 Bayliner Capri

Your motor has been hacked. Those engines are normally a closed cooled system.
Engines do not like to be run cold. Those engines should run at 185-190?
He didn't do you any favors.
 

axisg

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May 22, 2013
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Re: AQ131a & Penta 275 Missing Cooling system ?? 1987 Bayliner Capri

After a few phone calls I located a parts boat 2hrs away. They have the parts I need plus some other items I am missing ( some brightwork, horn, ladderbars ). Debating on when to do the drive

How much damage can be done by running the boat this way ? Its only operated in fresh water and stored on the trailer when not in use.
 

Don S

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Re: AQ131a & Penta 275 Missing Cooling system ?? 1987 Bayliner Capri

How much damage can be done by running the boat this way ?

Have no idea, never seen one like that before.
 

Nickypoo

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Mar 21, 2012
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Re: AQ131a & Penta 275 Missing Cooling system ?? 1987 Bayliner Capri

Look up a user named "paperklip". He had the exact same scenario. Corrosion ate through the aluminum head, so he replaced the block and replaced the missing cooling parts with aftermarket stuff.

You definitely do not want to run it this way. That is indeed hacked up.
 

axisg

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Re: AQ131a & Penta 275 Missing Cooling system ?? 1987 Bayliner Capri

Have you ever heard the saying " a little knowledge is a dangerous thing ??"

Thank you for the great read ! But now this " little bit of knowledge " has kicked my OCD into overdrive. I would now love to pull the intake and exhaust off to check the condition of the head. But If I am going that far I may as well pull the whole unit out, break it apart and reseal it all up. But since its going to be out then it only makes sense that I should break it down and send the motor to the shop to be hot-tanked, and honed, new rings. And the outdrive sent to the shop for new bearings , u-joints, maybe a new prop......LOLOLO

For now, my puny wallet states that's not going to happen. Instead I have emailed a request into the boat salvage yard ( closest one with parts I need is 2 hrs away ) for the heat exchanger and related bolts, brackets, ect....

Next on the to-do list is figure out why the bottom back of the block is wet with oil ( I suspect rear main seal ) and why the oil in the outboard looks a little milky ( pressure test ). After the last trip out I noticed about a tablespoon of oil in the bilge

Wifey and kids are dying to go fishing this weekend. Too many things with too little time.
 

Nickypoo

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Re: AQ131a & Penta 275 Missing Cooling system ?? 1987 Bayliner Capri

If you only use it in fresh water, the head may be in good enough condition to just reinstall the closed cooling system and leave it at that. Just try not to keep running it that way.

I know how it is. You go to fix one thing and then you decide to fix something else "while you're in there". Pretty soon the whole boat is apart. Lol.
 

axisg

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May 22, 2013
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Re: AQ131a & Penta 275 Missing Cooling system ?? 1987 Bayliner Capri

I made the drive out to the boat salvage yard and pulled the heat exhanger , lines, and related brackets.

Last night I spent 2 hrs getting it all back together as the factory intended. At the same time I also replaced the impeller & thermostat.

Sea Water side bolted back together fairly well. The only issue I can see is the return line from the heat exhanger to the copper line is a press-fit and it's leaking a steady trickle ( it seems pretty common from what I have read ). I have ordered some new rubber seals for that.

The engine side seems to be sealed. Its holding water in the tank, with no visable leaks.


So I proceeded to dunk the outdrive into a rubbermaid bin full of water and fired it up.

The impeller seems to be pumping fine ( lines are cold, water is spitting out the exhaust at a steady rate ). The leaking line from the exhanger to the exhaust leaked a little worse but that can be fixed.

However I had noticed that after 5-10 then 20 mins that the temp guage had still never moved off the coldest setting on the guage (It was working last week when the impeller let go as the temp rose rather quickly ).
I opened the rad cap a couple times while it was running to see if the system had burped and add water and it only took 1 small top-up after about 5mins runtime. I noticed no water movement in the heat exhanger while the rad cap is off. The lower rad hose from the exhanger to the engine water pump is hard with the rad-cap on so I know its getting somewhat pressurized. The water in the tank was warm after 20 mins but definately not hot.

I will poke around this weekend and see what turns up. Maybe the engine driven water pump is finished ( although that would overheat the engine in no time I would think )? Or the thermostat is stuck open or dislodged during install ??
Per the thermostat I noticed during install that the thermostat looks to be installed backwards to me. On a car engine the spring side is typically in the block but in this application it will not fit in the block but instead it sits in the neck of the heat exchanger which seems weird to me.

I have some pics on my phone but left the cable at home :)
 

Nickypoo

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Re: AQ131a & Penta 275 Missing Cooling system ?? 1987 Bayliner Capri

The way you have the thermostat should be the right way. I think it only fits in there one way and the spring side is out.

Check your gauge to make sure it's still working. That's the only thing I can think of. Maybe the connector isn't tight.
 

axisg

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May 22, 2013
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Re: AQ131a & Penta 275 Missing Cooling system ?? 1987 Bayliner Capri

well I pulled it apart today trying to seal up that one leaking line. I discovered that the BN thermostat I put in actually came apart with the thermostat coming away from the housing ( looks like a press fit that didn't work so well ). I soldiered on and spent a good 2.5 - 3 hrs today and it took me 3 tries, many curses and one threat to drag the boat to an abandoned area to set it on fire but its holding water now. Whoo-hoo!!! I used the thermostat from the "donor" engine which I had pulled the heat exchanger from in the rebuild.
I fired it up. The engine now gets up to 175 deg and holds the temp. The motor seems to hold pressure on both the engine and sea-water side now with no noticeable leaks. There is an ever so slight trickle which was coming from the rad cap that went away after about 20 mins of run time. Hopefully if the weather holds tomorrow I will launch the boat on Lake Ontario for a quick workout.
 

Nickypoo

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Re: AQ131a & Penta 275 Missing Cooling system ?? 1987 Bayliner Capri

Good stuff. Good luck tomorrow.
 

2stroke1971

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Re: AQ131a & Penta 275 Missing Cooling system ?? 1987 Bayliner Capri

Wow man, that hacked version was cool! LOL.....Hmmmm.......I should NOT have looked at that!
 

axisg

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May 22, 2013
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Re: AQ131a & Penta 275 Missing Cooling system ?? 1987 Bayliner Capri

ll I finally got it back on the water yesterday ( Sat ). There was nobody there so I ran the boat for 15 mins at the boat lauch and the lines held firm and dry. I replaced the engine cover and went out on the lake for about an hour while staying pretty close to the boat lauch just in case. All the guages stayed in the normal range but I noticed a slight miss-fire when we arrived back to the lauch. I opened the cover and had about 4" of water in the bottom of the boat and sprayed over the engine. The line had backed off somehow so I cut the day short and put the boat back on the trailer. There has got to be a better system to seal these lines up. I have considered cutting the line and using an adhesive to bond it into the plastic fitting. The 2 copper lines could then be joined with a length of hose and clamps.

The engine is still leaking some oil as well ( I would geuss there were 3 tablespoons of oil on top of the bilge water ).
 
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