85 volvo penta aq125a with many problems

[Mullin]

I have a (new to me) 85 bayliner with an AQ125A volvo penta and it has a couple problems.

1. Motor dies at about 2000 rpms. It idles great, it revs high and runs high rpm great, but if I throttle in between 1000-2000 rpms slowly, it dies. It starts right back up no problem. When it dies it doesn't sputter, its like I turned the key off.

2. There is no water in the heat exchanger and it is slowly overheating. I replaced the impeller and thermostat and ran it with earmuffs. I think that because it has the closed coolant system, it kept it from overheating right away, but it hit 180 and then up to 200 after running for 10-15 mins. I shut it down then and repeated it later.

3. Leaking oil onto the fanbelt. Valve cover gasket, cam seal, and crank seal are the only three options right? Am I missing something else? I can't see a leak anywhere but it is making a hell of a mess. I just changed the engine oil and the oil is perfectly clean on the dipstick while the oil leak is black dirty oil. Even after running for 15 min the dipstick is still showing nice clean oil, which seems wrong. Oil pressure is 40 at idle and ramps up higher with rpms, 80psi at 5000rpms.

4. Overcharging at high rpm. I saw the gauge hit 16volts at 5Krpm. I figure this is just a regulator problem but didn't want to leave it out.

Any help or ideas would be most appreciated.

I'll try and take another look for the oil leak, but if its a cam/crank seal then I'm going to have to take it in since you apparently need a couple of specialty tools to remove the pulleys and seals. If I can solve any of these issues before I take it in then maybe I can save some money.

Thanks,
Jeff

 

[Don S]

Re: 85 volvo penta aq125a with many problems

1. Motor dies at about 2000 rpms. It idles great,

Idle rpm should be around 900 rpm, if you can't get it below 2000 rpm without it dieing, it doesn't idle at all, let alone great.

2. There is no water in the heat exchanger and it is slowly overheating.

Look at the hose connection on the drive, right where the hose from the engine hooks to the drive. That aluminum hose connector corrodes away and allows the pump to suck air, not water. Common problem.

Valve cover gasket, cam seal, and crank seal are the only three options right?

Well, you are there, which is it, I sure can see which one is leaking.

4. Overcharging at high rpm. I saw the gauge hit 16volts at 5Krpm. I figure this is just a regulator problem but didn't want to leave it out.

Remove the altenator and take it to your local starter/alternator repair shop (NOT an auto parts store) they can usually fix it for way less than the cost of a new one.

 

[Mullin]

Re: 85 volvo penta aq125a with many problems

Thanks for the replies guys!

I'll check the hose fitting tomorrow, send out the alternator, and look a bit closer to try and determine where the leak is coming from.

The 'dies at 2000 rpm' issue still has me scratching my head though.

Idle rpm should be around 900 rpm, if you can't get it below 2000 rpm without it dieing, it doesn't idle at all, let alone great.

It idles at right about 800 rpm nice and smooth.
It revs high and runs fine at a high (3000+) rpm.
If I ease into the throttle to about 1500 - 2000 rpm, the motor dies.
If I run at a higher rpm and then throttle back to about 2000rpm the motor dies.
When it dies, it just turns off. No sputtering (which makes me think its not the carb). But what else could it be? Anything I could test? It's a pretty simple carb but I'd hate to rebuild it without being more sure.

Thanks again.

 

[Don S]

Re: 85 volvo penta aq125a with many problems

Get your electical system down to 14 volts like it should be, do a full tuneup (points are probably getting burned with the high voltage, and do a compression test. Then see how things are going.
IF you don't have a water seperating fuel filter, you need one, and you may very will need a carb rebuild. Does the accelerator pump squirt gas when you pump the throttle?

 

[Mullin]

Re: 85 volvo penta aq125a with many problems

I have the Alt out to be rebuilt. I changed the plugs and inspected the dist cap, rotor, and points. I would have just swapped in some new stuff but these Volvo parts are crazy expensive ($60 dist cap!). It all looked pretty new and very minimal wear. Actually the points are only $10 so I'll get a set of them ordered. I also added a fuel filter/water separator as there was no fuel filter at all before. Yes, it does squirt gas when I pump the throttle.

I inspected the metal hose connector for the sea water pickup and it looks good. It actually looks really good and had already been replaced by the previous owner. I'll try flushing it to see if it has any leaks anywhere.

I took another look for the oil leak. Cam seal is not leaking, either is the valve cover, nor is the sprocket behind the seawater pump. The only thing I can't see without a mirror is the crank, but there is no oil on the back side of the crank pulley. Oil leaks are usually pretty obvious, but this one is not and makes me think I am missing something obvious.

 

[Don S]

Re: 85 volvo penta aq125a with many problems

Once you get the alternator on and get the engine running, make sure the point dwell is on 62? or 63? and the timing is set to the proper spec. The dwell tolerance is more than that per the book, but they sure run better at 62? or 63?.

For the oil leak, you're going to have to run it under load when warm then you well find it.

 

[beanomuntz]

Re: 85 volvo penta aq125a with many problems

I have that same motor in my 83 bayliner. The sea water system on my boat wasnt working so i checked the impeller and it was good but i took the whole pump off the engine and there is a shear key on the motor side of the pump shaft that was bad i replaced that and it work great.

 

[Mullin]

Re: 85 volvo penta aq125a with many problems

The dwell tolerance is more than that per the book, but they sure run better at 62? or 63?.

OK, thanks for the tip.

a shear key on the motor side of the pump shaft that was bad i replaced that and it work great

If I can't find a leak in the intake pipes then I'll check that next.

For the oil leak, you're going to have to run it under load when warm then you well find it.

I was thinking that I'd go ahead and run it with the alternator off. The drive belt was throwing the oil all over and making a hell of a mess, so it should be easier to see a leak without all that going on.

 

[Mullin]

Re: 85 volvo penta aq125a with many problems

-Update-

I connected a garden hose onto the seawater system this morning and found the leak. It is on the out drive where the hose connector attatches to a plate, but not there, the leak is from under that plate. The best I can describe; it is just above and behind the prop, the hose connector looks similar to a t-stat housing with 2 bolts and a hose connection and is attached to a plate, this plate is then connected to another piece and that is where it leaks, between the 2 plates. I hope that makes sense. Here is a diagram, the connector is #53 but I do not see the plate to plate connection http://www.volvopentastore.com/mall/image/view/7/8/7464_1.png

While I have that diag up here: there is a pinhole leak in the exhaust boot #76, is that worth replacing for $85? It is squirting water from there when I have the water hose hooked on. I think I have read that there is supposed to be a pinhole for drainage, is that true?

So I ran the motor and still can't find the oil leak, however I did find something else. The timing belt tensioner pulley is seized (so that's where all that smoke is coming from... the belt is burning! :\ ). I can't find replacement parts for the timing tensioner, any suggestions?

 

[Don S]

Re: 85 volvo penta aq125a with many problems

That "Plate" is probably the H fork for the drive. There is a bushing in it, if there is too much play, it will cause the gasket under the hose connection to leak.

Don't run the engine with the belt off the alternator, that is what runs the engines circulation pump. Without it, the engine will overheat.
You are not going to find the oil leak running for just a few minutes on muffs or on the floor. It needs the get warm and some rpm to find leaks.

there are no parts for the tensioner. You replace it as a unit.

Yes, the exhaust bellows may have a round drain hole in them.

 

[Mullin]

Re: 85 volvo penta aq125a with many problems

OK thank you Don, your help is very appreciated. I have not been able to find either tensioner parts/unit here on iboats or in the sierra catalog, nor the bushing on the H fork. Any ideas were to find these parts? Google has not been much help either.

 

[RogersJetboat454]

Re: 85 volvo penta aq125a with many problems

OK thank you Don, your help is very appreciated. I have not been able to find either tensioner parts/unit here on iboats or in the sierra catalog, nor the bushing on the H fork. Any ideas were to find these parts? Google has not been much help either.

Volvo would be the best place. Iboats has the "Volvo Penta Store"
http://www.volvopentastore.com/Mari...*****.408971809--store_id.366--view_id.765162

This is the break down for your t-belt;
http://www.volvopentastore.com/Belt...*****.408971809--store_id.366--view_id.784398

Make sure you replace the belt with that tensioner. As a side note you may find that Volvo 240 series car parts will work fine and be much cheaper!

A gates timing belt kit which includes the belt and tensioner for a 1985 Volvo 244DL is $25 bucks at Rockauto.com.

Edit: I confirmed Gates uses the same timing belt (TO32) between the 1985 AQ125A, and the 1985 Volvo 244DL car.

 

[Mullin]

Re: 85 volvo penta aq125a with many problems

A gates timing belt kit which includes the belt and tensioner for a 1985 Volvo 244DL is $25 bucks at Rockauto.com.

That's great, thanks! I can't believe how much the same stuff goes for at boat sites...it's crazy.

 

[Mullin]

Re: 85 volvo penta aq125a with many problems

So back to the water leak. It is definitely the bushing on the yoke under the hose connection, you can see it here (#11): http://www.marinepowerservice.com/B...D=193326&parent_cat=451321&parent_cat1=451322

Looking through my manual, it is not an easy fix and requires removing the drive from the transom and you need a press to remove the shaft where the bushing is. This is my first I/O and I am wondering if this is something I can expect to accomplish in my front yard myself, or should I just take this to a shop where they can probably have this done in 2 hours? I am leaning towards the latter, but would like to supply the parts to ensure a quick turn-around. What parts would be deemed a necessary replacement/ disposable item? The list I have come up with is: (parts in diagram linked above)

# 29, 11, 25, 16, 13, 13, 24 and then a bushing kit 38, and o-ring 34.

I was wondering if this sat below the water line I wouldn't even need to repair it, but it looks too high up. Seeing as I have never even had this boat wet, I'm not going to chance it.

Any suggestions? How's my parts list look? Thanks guys.

 

[Mullin]

Re: 85 volvo penta aq125a with many problems

1. Motor dies at about 2000 rpms.

2. There is no water in the heat exchanger and it is slowly overheating.

3. Leaking oil onto the fanbelt.

4. Overcharging at high rpm.

---Update---

I took the boat out on the water Sunday and again today, had a great time! Thank you guys (Don S!) for all the help. I still need to rebuild the carb and already have a kit for it, but I was able to get out and enjoy it for a bit. So here's what happened:

1. This is still a problem but I found that I can feather the throttle to get past the finicky accelerator pump. Rebuild kit is in hand and I'll get this done soon. Any tips for rebuilding a single barrel solex carb? It looks very simply but there are always tricks.

2. The lack of water was from a leak at the bushing under the yolk, and the fact that I was testing it on muffs. In the water, there is no problem at all, the leak is below the water line, plus when I had the muffs on I didn't see the extra hole in the bottom of the outdrive. I replaced the hose connecting the outdrive to the motor with a clear 1" tube and there aren't any air bubbles underway.

3. Oil was leaking from the front bottom of the engine where the timing cover plate meets the oil pan. I cleaned it off real good and put down a bead of silicone. Then I tightened up the 4 bolts accross the front of the pan, they where a little loose. No more leaks.

4. I had the Alt rebuilt, for 120 bucks, I should have just replaced it with a delco alternator but it's done.


Sorry for the wall-o-text but wanted to let you know what happened. I have another question too, I live in high altitude (6750ft on the lakes surface) and it's pretty normal to have to change the prop to get the rpms into the correct range for full throttle up here. I was doing 28mph at 4600rpm, what is the accepted range for full throttle on this aq125? Thanks again.