AQ125A 83 Bayliner Capri 1950 Stalling

[Jolie Lynn]

Hello all. First time poster here and hope I can help someone sometime in some way. This is my first boat. I have a 1983 Bayliner Capri 1950 with a Volvo AQ125A/270. She has been out of the water for years but have done a lot of work and have been having a blast so far but I can't seem to figure out why the engine hesitates then stalls in gear in the water from the first detent in throttle position forward and reverse. If I goose her a little I can get past that dead spot. I see the accelerator pump pushing gas out the candy cane from that detent to full throttle just fine. I have a new fuel pump, wires, plugs, and gas. The points are gapped correctly. I looked at the accelerator pump diaphram and housing and they look fine. Could it be a timing issue? I have read posts for hours and need help soon I have a few other questions but will only post one at a time, I think that is what I am supposed to do.
Thanks so much,

 

[havasuboatman]

Re: AQ125A 83 Bayliner Capri 1950 Stalling

What are the RPM's at when idling, in the water, in gear?

 

[Jolie Lynn]

Re: AQ125A 83 Bayliner Capri 1950 Stalling

Hi !! The RPM's are about 900-1000 at idle. When I start to accel I feel the drive engage (Softly) and she starts to move at a constant no wake pace untill about 1/4 throttle I feel a detent. From that detent the RPM's start to increase but if I advance slowly it seems to (sounds like) sucking more air than usual, sputters then dies out. If I quickly get past that spot everything runs awesome up to 4950-5000 RPM WOT. I am asuming that RPM is OK I have not been able to find the true WOT for this engine or true HP. I put B-12 fuel additive to the tank and filled it up. I have only used 1/4 tank on that treatment so far.
Thanks a bunch.

 

[captmello]

Re: AQ125A 83 Bayliner Capri 1950 Stalling

Go to this link and enter aq125a in the engine type box. There is some good info there to download.

http://www.volvo.com/volvopenta/global/en-gb/marine_leisure_engines/parts_service/publication_search/publication_search.htm

You said you gapped your points, did you use a dwell meter? If not I would recommend it. This does effect the timing and the timing would need adjustment as well. Not saying this is your problem but...

Good luck too you!!

 

[Jolie Lynn]

Re: AQ125A 83 Bayliner Capri 1950 Stalling

Wow that is good info!!!! Thank you. I did not set the dwell but found on that link that I am using the wrong drive oil. I have marine 80W90 and it calls for 10W40 the same as whats in the engine. The drive could be bogging down the engine. I will start with that before anything else. I will keep ya posted

 

[Jolie Lynn]

Re: AQ125A 83 Bayliner Capri 1950 Stalling

Well we took her out today and it did not fix that problem. I will try to check the dwell and timing next. Today I put 3/4 tank, two adults, four kids and lots o stuff onboard. It pulled the kids on tubes wonderfully. The engine was turning at 2400 RPM and getting 32 MPH. Is this OK? This boat has no problem getting 4950 RPM and 34 MPH WOT with a small load or no load. Should I get a smaller pitch prop to get the engine RPM's higher or is this normal for a fully loaded boat 26 years old? If I could get a couple more MPH that would be great but I fully understand if not
If anyone else has this boat or engine and has questions as to what I have experienced and can help let me know. I check this site about every other day.
Take care

 

[robjen1019]

Re: AQ125A 83 Bayliner Capri 1950 Stalling

At 2400 rpm your going 32 and at 4900 you are going 34, Something is wrong with this. I wonder if you are over propped and the prop is slipping.

At 2400 the speed should be about half that at 4900

 

[captmello]

Re: AQ125A 83 Bayliner Capri 1950 Stalling

The engine was turning at 2400 RPM and getting 32 MPH. Is this OK? This boat has no problem getting 4950 RPM and 34 MPH WOT with a small load or no load.

Do you mean 4200 RPM getting 32 MPH?

Those numbers seem okay for a boat that size with a four cylinder. If you were running with a fully loaded boat all the time you could consider a smaller pitch prop, but you would be over the top RPM limit with an empty boat.

4950 RPM is at the top of the scale for RPM's for that motor so if you went to a larger pitch you may up your speed and lower your RPM but you would sacrafice your hole shot.

I would suggest finishing the dwell and timing adjustments, and go from there. It may not fix your hesitation issue, but it may effect your top speed. If the boat still has the hesitation, you may be looking into a carb rebuild, not a big deal.

Good luck.

 

[Jolie Lynn]

Re: AQ125A 83 Bayliner Capri 1950 Stalling

Thanks guys,
I am pretty sure it was 2400 RPM. I thought it strange also but was too excited to see going over thirty with a full load I do not know the prop pitch but it is about 13 1/2 to 14 inches in diameter. I will take the spare into a shop this week to find out.

 

[Jolie Lynn]

Re: AQ125A 83 Bayliner Capri 1950 Stalling

It's a 14X19 prop..

 

[jerryjerry05]

Re: AQ125A 83 Bayliner Capri 1950 Stalling

Do you have a water /fuel seperator filter.It sounds like you might have some water in the system.J

 

[captdre]

Re: AQ125A 83 Bayliner Capri 1950 Stalling

Do you have a water /fuel seperator filter.It sounds like you might have some water in the system.J

X2 I had a similar problem, 1980 aq145a, the water separating filter will fill with water adn hold it so there may not be any in the tank but it will be in the filter and getting to the engine from there. but mine would stall randomly.
when my head gasket blew, I lost compression on 1 cylinder and she wouldnt idle right but if i gave it gas it sounded fine. did a compression test the kind that screws into the spark plug holes and found a cylinder with half the compression of the others.
good luck

 

[Jolie Lynn]

Re: AQ125A 83 Bayliner Capri 1950 Stalling

Hi,
It does have a seperator. I installed it new and have only been through 3/4 tank of good gas. I will check it to see. I put B12 additive into the gas it has used. I just checked the timing and it was about 15 BTC so I brought it back to what the book calls for....10 BTC. I set it at a smooth running 900 RPM idle speed. I found that the stalling still happens at 1100 RPM when RPM starts to dwindle until throttle brought back or pushed forward. I did notice some smoke with the water spray out the exhaust. Never saw that before. The person I bought the boat from was trustworthy so far and said the compression was in range and 1PSI to less than 1PSI difference between the cylinders(well balanced). This engine runs, idles, and performs great other than this issue I will re-check the compression, fuel seperator and maybe tweak the carb some and if nothing helps....Well I will just live with this prob:redface: I will do All this and a run in the lake hopefully by weekend. I am taking her to the North Carolina sound in two weeks and want it to be reliable. I will keep this thread posted as much as possible along the way
Thanks All
Thanks All

 

[warlock73]

Re: AQ125A 83 Bayliner Capri 1950 Stalling

I hope this helps. I had a very similar problem. In the process of singleing out a starting issue, which wound up being the starter coil. That was after replacing the distributor rotor, points, condenser. It runs smmooooooth now. Hope this helps save a few bucks. Oh, and last but not least..take a file to the inside of the dis. cap.

 

[Jolie Lynn]

Re: AQ125A 83 Bayliner Capri 1950 Stalling

Well.... took her out last weekend with making two adjustments. 1. I set the timing to 10 degrees BTC at 900 RPM per manual. 2. for some reason wanted to try the FWD hole on the outdrive lock pin. It was bogging down badly and started to over heat. I set it back to the original middle hole (of the three selections) and was getting close to 40 MPH on 1/4 tank just me in the boat. Never saw that speed to date. I still have the hesitation and stall issue though. I do not have a dwell meter and have not set that yet. The timing is 10 @ 900RPM and 28@ 1800 RPM with 87 octane ???normal???guess so My distributer and point system seem and look good. I will re-build the carb in about a week or so. Will keep this post posted

 

[Jolie Lynn]

Re: AQ125A 83 Bayliner Capri 1950 Stalling

Hi all,
just keeping this thread to help anyone else that experienced the stalling thing. I rebuilt the carb ((sierra p/n 18-7000)from Iboats)and cleaned thoroughly!!! I could not use the new accel pump diaphragm because it was sooo thin and flimsy that I could not keep the fuel from running out all around the housing. The old one is very stiff but thicker and still works. The initial test on land cured the stalling but the true test is in a couple days back on the lake. I think I figured out the rpm problem. The dial on the back of the tach was on 8 not 4. Thus probably reading v8 cam and cutting rpm's in half:redface: I will post one more after this trip if it works and maybe this info will be of some use.

 

[Jolie Lynn]

Re: AQ125A 83 Bayliner Capri 1950 Stalling

REBUILD THE CARB!!!! It worked and the motor ran smooth without hesitation even with creeping the throttle as slow as I could. Still have the tach issue but will start another thread on that. I hope this helps someone somewhere.
HAPPY BOATING