Aq125 carb issues?

[soccer082004]

Hi, I have an 86 bayliner with an aq125b with the single barrel solex carb. My issue is the motor starts and idea fine. Wheni give it gas fast it kind hesitates and sounds like it sucks air. Slow acceleration is ok. I rebuilt the carb and no change.

Any ideas!

 

[Mullin]

Re: Aq125 carb issues?

Mostly just the accelerator pump adjustment. The mixture screw will effect it a little too, so once you have the idle and mix set good, then adjust the accel pump. Back out the nut to have it engage faster.

Of course your ignition needs to be in good order and timed right too, it will be a real struggle to get the carb to compensate if it's a timing issue.

 

[soccer082004]

Re: Aq125 carb issues?

Oh yeah I forgot, I just timed it and it matches specs perfect with the timing light, still same problems. Do you know when things need to be adjusted to?

 

[Mullin]

Re: Aq125 carb issues?

Do you know when things need to be adjusted to?

What?

Good, timing is set, now adjust the carb. There are 3 adjustments: idle, mixture, and accel pump.

Start by warming up the engine. Set the idle (900rpm in gear in the water, or close to 1100rpm at idle on muffs). Then adjust the mix a little to see if it sounds better a half turn either way. When the mix is right it will probably bump up the rpms a little. Readjust the idle. Then adjust the accel pump.

If you punch the gas and it hesitates or stalls, the accel pump is probably not squirting gas on demand. You need to back off the adjusting nut on the rod to make it squirt the gas sooner. There is a point where too soon is not good either, just tweak it for a few minutes and you should have it figured out.

 

[soccer082004]

Re: Aq125 carb issues?

Hey guys, I can see that the accelerator pump is squirting but I'm not sure if its enough. I tried all adjustments and still the same problem, any chance it's a vacuum leak?

 

[Mullin]

Re: Aq125 carb issues?

Not many places for a vacuum leak, just the intake manifold gasket and carb mounting gasket. You can blow smoke at it and see if it gets sucked in anywhere.

 

[soccer082004]

Re: Aq125 carb issues?

Ok i think I figured it out! The spring on the accelerator pump shaft is very weak and wouldn't push out the arm when throttle was applied. Got a stiffer spring and worked great!!!