Volvo Penta AQ125 no power?

flyinsweed

Cadet
Joined
Mar 9, 2014
Messages
8
Hey guys I have a Bayliner Capri 2.1 with a Volvo Penta AQ125 and am having some issues with my power/ acceleration. I have done a carb clean/ rebuild and have set the air idle screw where the book tells me and adjusted accordingly. I now am having a hard time getting up to speed? The boat takes a minute to get on a plane and only goes about half throttle after that there isn't any more reaction to the speed or RPM's. So from idle to half throttle works "ok" but that's it. Can someone help please!?
 

flyinsweed

Cadet
Joined
Mar 9, 2014
Messages
8
Plenty of fuel in the carb. Runs smooth and ildes good. Just doesn't have as much power as it had before. It was running on a fuel starved system and had been tunes to that. Was curious if maybe I should check the timming. Working on a tachometer issuse or I'd do that right now, but I have another thread going for that.
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
18,146
What prop is on there?
Maybe the hubs spun?/
Did it ever work right?
What if anything did you do to the motor?

​These lower power Volvos need the right prop.

A neighbor called and said his 125 Volvo wasn't operating right.
Did all the tests.
Found nothing.
As I was putting away my tools I noticed a prop laying on the ground.
I asked when was it changed.
It was changed the day the trouble started.
The new prop was the same pitch but way different design.
The blades were about twice the size of the new prop.
It needed the sweep of the longer blades to get the motor operating right.
Maybe this might help?


Compression test?
 

flyinsweed

Cadet
Joined
Mar 9, 2014
Messages
8
The boat ran great at the beginning of spring last year and started having some fuel issues at the end of the fall fishing season. It would top out at 38mph at the start of the year but dropped to a top speed of about 28-30. I put a new fuel pump and filter on and also did a carb rebuild, set it back to factory settings and adjusted while the motor was warm. Now I only have a top speed of 25 at best and it is very slow to get on a plane with only two people in the boat. I've done a compression test and I am getting between 178-180 in all 4 cylinders, which is way better than what the book says it would have. I've also check for fuel in the float bowl and I seem to be getting a sufficient fuel supply. I'm wondering if I have the timing off due to tuning the motor on a fuel starved system?? Could I have a bad coil, if so how do I test that?? How do I check the prop?? Thanks for your input, all is much appreciated!
 

Maclin

Admiral
Joined
May 27, 2007
Messages
6,761
What exactly was done when "tuning the motor on a fuel starved system" ? Was the distributor moved? Were the points adjusted?

I would do an electrrical tuneup with new points and condenser, set the dwell then set the timing and see what is what after that.
 

flyinsweed

Cadet
Joined
Mar 9, 2014
Messages
8
Yes I adjusted the distributor, I switched the points out for an electronic ignition when I first bought the boat 4 years ago, which made the start up way easier. I didn't want to move the distributor again without talking about it with some of you guys. I am not a mechanic but have managed to fix most of the issues I've had with my boat and trucks, but always like to get feed back from others who may know better than I do.
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
18,146
If you adjusted the dist. then look that way.
​If you changed the prop?? Then maybe that could be the problem?
Once you get up on plane?
Does the motor rev up and no forward motion?
If so then the prop hub could be going bad?

A bad coil: get the motor running and up to temp.
Then touch the coil. It shouldn't be so hot you can't keep your fingers on it.

Post a pic of the prop.
 

flyinsweed

Cadet
Joined
Mar 9, 2014
Messages
8
No rev up on the motor after plane. Everything feels smooth just no power, takes a few to get to "full" speed. I will check the coil today after work and post a pic of the prop. Thanks again!
 

Maclin

Admiral
Joined
May 27, 2007
Messages
6,761
Yes I adjusted the distributor, I switched the points out for an electronic ignition when I first bought the boat 4 years ago, which made the start up way easier. I didn't want to move the distributor again without talking about it with some of you guys. I am not a mechanic but have managed to fix most of the issues I've had with my boat and trucks, but always like to get feed back from others who may know better than I do.



Then from my suggestion jump to here...: "...set the timing and see what is what after that."
 

dennis461

Chief Petty Officer
Joined
Aug 11, 2011
Messages
516
throttle plate opening all the way?
timing belt jumped a tooth.
xhaust clogged at rubber connection inside boat.
xhaust bellows crushed?
spark plug gap?
all 4 cylinders producing power? (pull one plug at a time with thick rubber gloves IF THERE ARE NO FUMES IN BOAT)
 

flyinsweed

Cadet
Joined
Mar 9, 2014
Messages
8
Having a hard time getting the pics off my phone, I will have to put them on my computer and upload that way.
 

flyinsweed

Cadet
Joined
Mar 9, 2014
Messages
8
ok so I guess the file is too big to load the pics, even one at a time!? Not sure what the deal is with that.
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
18,146
You can resize the pics on your computer then transfer to here.
​Or send me your e-mail in a PM and I can see the pics then??
 
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