AQ 125 acceleration problem

[nwbayliner1122]

I have been trying to solve a long term problem with my solex 44pai carburetor. The symptoms are these: the engine starts up and will rev up in neutral easily while cold, but does not like to rev from 1000 to 2000 rpm in gear (engine stalls) until it is fully up to temp (180-190 on the gauge), if it stalls in this manner it will usually not want to start for 5-10 minutes which I believe indicates that it is flooded and there seems to be no way to get it to start (tried cranking with the throttle wide open). I believe this is probably an accelerator pump problem but am hoping somebody might be able to tell me some tests or what to try next. I have also thought I might try changing the idle mixture settings and see if it helps. Any ideas or advice would be greatly appreciated, thanks!

 

[alldodge]

It might be the carb, but would I would think it would be the float setting more then the accelerator pump. Do you know how the motors compression is?

 

[kenny nunez]

If the idle mixture screw is more than 1/4 either side of 1.5 from seat then something is definitely wrong. As AD said you should test the compression. If the readings are close to each other then go ahead and get the correct rebuild kit for the carburetor. It is a pretty simple carburetor but you must remove all the jets and and small parts to clean them.

 

[kenny nunez]

If you look closely at the starter solenoid there is a male spade connector @ the 2-3 o”clock position. If you connect a wire from it to the + or BAT side of the coil the engine will be easier to start. This is the by pass circuit which feeds 12 volts to the coil when cranking. Bayliner used a cheap wiring harness in place of the Volvo harness which had the circuit in it.

 

[nwbayliner1122]

Well, I played with the idle mixture screw a bit, and it's hard to say but it might have improved the acceleration a little. I also tried the wire from the solenoid to the coil and wow! It starts immediately now, I am amazed and thank you for that tip! I never thought that this might be a sign of compression issues because the engine runs smoothly and revs up well, but I guess the whole acceleration stalling could be from not enough power? I just cleaned the flame arrestor which was filthy and sprayed some seafoam in the carb, plus I cleaned all the barnacles off the bottom, might test run again on Saturday and play with the settings some more. Thanks for the tips.

 

[kenny nunez]

The idle mixture screw only controls idle only. If there are barnacles on the bottom they must be removed. All the power is being wasted to over come the drag. Most times the flame arrestor gets clogged up with material from the alternator belt especially if the pulleys are rusted. Keep a close watch on the belt. Good luck

 

[dennis461]

I'm pretty sure the single adjustment screw version of the carb, has two functions, idle and mid-range .
I used to have a problem with mid range until I backed out the adjustment another 1/2 turn above good idling.
If I leave the carb on the boat over winter, I have problems and then need to re-clean again



As for hard to restart, check inside the dist cap for any gunk. I would not bypass the ignition resistor, the points will not last long, and your just masking some other problem.How old are the points?

What's the air temperature when you have problems?

 

[kenny nunez]

The “bypass” circuit is for starting only, when the ignition is in the run position the voltage reverts to whatever the resistor delivers to the coil.
All ignition systems have to have voltage in cranking mode, whether it is fuel injected electronic ignition systems or breaker point.
Volvo carburetors tend to gum up while in storage and need yearly attention. There is a hex plug in the bottom of the float bowl that can be loosened to drain the bowl and may help with preventing the gumming up problem.

 

[nwbayliner1122]

Well, I cleaned the flame arrestor and smoothed out the alternator pulley, scraped the barnacles off and cleaned and painted the prop. Test ran on Saturday and it did run slightly better but still wants to stall before up to temp between 1400 and 1900 rpm, if you don't really baby the throttle. Once up to temp it is not a problem. I recently spoke with a local marine engine mechanic, and he told me that the solex carburetors are just cold blooded and that this type of problem is just a normal thing with these older volvo pentas. He said he tells people the solution is to get out the newspaper and pour a cup of coffee. I guess I'll just live with it? Thoughts?

On another note, I am having an issue with the throttle/shift mechanism where it won't shift into forward immediately, I often have to rev up a bit before it actually shifts into forward. Shifting into reverse seems to work okay. I would take a look at the mechanism itself, but Bayliner has made it pretty inaccessible. Has anyone ever had this problem?

 

[alldodge]

With the shifting is most likely needs to replace the lower shift cable, could try to adjust to see if that would help, but its a common issue

So far as living with the carb, he might be right, but then again, maybe it just needs the choke adjusted so it closes down a bit more. You still want it full open once warmed up.

 

[kenny nunez]

If you remove the cover on the drive and observe the action while someone shifts you see which way you have to adjust the brass fitting that is on the end of the cable to give it more toward forward. The cable goes all the way into the shift control so if the cable is the problem then you will have to get the control unit out.
As you can see there is no choke on your carburetor. It must be a real challenge for the Swedes to use these engines where it gets pretty cold.
These little engines must run at around 190 or it will not last.

 

[dennis461]

Did you read my previous post?
There is no choke, and my boat is warm enough to throw the throttle down without problems after idling away from the boat ramp. You should not have to life with a boat that stutters.

 

[alldodge]

Missed the no choke