AQ125B 2.3 Volvo idles rough until warm

[Sworsen84]

ok I know there's no choke on these carbs but it's really difficult to get it to start right up. I have to turn it over about 5times then it fires. Runs like crap then dies. I can do it again and then idle it up by pulling out throttle and speeding up the idle. After a few minutes it warms up and runs. The idle still goes up and down on its own every once in awhile. Is this NORMAL??

 

[yknotgosailing]

What carb do you have, if its a solex then yes pretty normal installing a primer bulb with check valve and giving it a few pumps will fill float bowl quicker hence it should fire faster. With no choke engine runs too lean when cold possibly icing a bit until manifold warms up. I got rid of my Solex installed a Rochester with an electric works much better.

 

[Sworsen84]

Yes It is a Solex. How hard was it to switch over to the quadra jet? Which model did you use?

 

[jerryjerry05]

Try setting the low speed air screw.
Turn the air screw in until it bottoms(GENTLY) remember the turns to the bottom.
It shouldn't be more than 2 whole turns.
Set it at 1 and 1/2 turn out.
Once you get it warm, turn the air screw in 1/8th of a turn.Wait 10 seconds for the fuel air to settle
and then again till it coughs or sputters and then back out 1/2 turn.
Wait 10 seconds between turns.

I've found that a squeezie ball will help.
But not really needed.
If you have long periods between use. Then it will really help.

Or. When go to start: Turn the key,(it starts pumping the fuel to fill the bowl) as it's turning over.
Pull the throttle handle out and push it forward and back (quickly)while it's turning over.
Do this quickly all the time your turning it over.. It will operate the accelerator pump pushing extra fuel into the carb.
It should make the starting easier.

Yours is a twin carb setup.
Changing to a single would be easy if you can find the intake and carb for a single carb.

The older Volvo 4cyl seem to be a bit cold natured.
IF?? nothing helps?? Starting fluid could help??
See how many comment about that??

 

[bruceb58]

Don't install a primer bulb. Illegal to have those in a bilge area.

 

[yknotgosailing]

Do you have the single Solex carb set-up, if so the change over is quite simple , requires a manifold adapter to allow a two barrel configuration, not a quadrajet though too much fuel. Got my carb and manifold from a supplier on eBay ,I'm sure I could find the source if your interested.
Not sure about the dual Solex carb option but you still might be able to convert and run two 2 barrel carbs of equivalent CFM
Wasn't aware of the primer bulb law learn something everyday still going to keep mine! As jerry jerry mentions first make sure the low air screw adjustment is correct if leaned out can cause the same symptoms to a degree.
If you haven't already switched your ignition dist from points to electronic I would also highly recommend it, dwell and timing are an issue with those distributors, Pertronix is good but Hotspark also makes a decent conversion, much cheaper.
One more thing check for any vacuum leaks does not take much on those engines to affect idle and surging, wifes or girl friends hairspray works great for that just don't tell her!

 

[Alan Lloys]

I have the exact same engine on mine.
It was a bit tough to start until I started following the correct procedure from the manual :facepalm:

I am not sure about the surging idle - that does sounds like a vacuum leak or carb issue.
Anyway in regards to starting the procedure is as follows:

Put the throttle in neutral and pump from low to hi 3-4 times.
This will squirt gas into the manifold from the accelerator pump.
Set the throttle at about 1/2 open.
Start the engine. If needed you can pump the throttle while cranking to get additional fuel.
Once started keep the engine at around 2,000 rpm until it warms up. This usually takes just a few minutes.

I usually drop the boat at the ramp, fire up the engine and then put the truck/trailer away. This way it will be about ready by the time I walk back.
The only time I have issues with starting is in the beginning of the season.
Otherwise my engine usually starts up on first or second crank.

 

[Alan Lloys]

Sorry to do 2 posts in a row.
I just wanted to comment on the carb change. I actually do not have any issues with the Solex as long as they are cleaned and adjusted properly.
I changed my engine over to the dual carb (Solex) from an AQ151. I also put a "V" cam in the engine and put on an oil cooler.
This effectively makes the engine into an AQ145 and gives you about 20 more hp.

It runs very smooth and has a bit of extra kick for a reasonable investment.
This modification really only works on the 2.3L engine which is why it was important for me to know for sure what I had.

 

[Sworsen84]

I was able to adjust the air mixture and even it out a bit, this is a single solex carb, I am switching over to the pertronix electronic ignition. I'm also going to rebuild the carb. It's always been hard to get going but once it's going it does great. Can't complain for an older boat