AQ260A idle question

I have twin volvo AQ260A engines. Purchased boat last spring. I have done the following:
Replaced plugs and wires.
Replaced distributor cap and rotor.
Replaced ignition coil on port, starboard appears to be relatively new.
Took off carbs, cleaned and put in new parts and gaskets from rebuild kit.
Replaced inline fuel filter and water separator filters.

Both engines are running great at cruising speed anywhere between 2400-3000 rpms. They both hold a very steady RPM, I have digital tachs, so I see it all.

Port Engine--
In neutral I have it set to idle at 550. It holds it well and only fluctuates by 20 or so RPMS, drop it into gear, it goes down to 440 or so and holds it well.

Starboard engine--
In neutral I have it set to idle at 700 or more. Fluctuates by 80 or more RPMs. I drop it into gear and it falls below 350 RPMs. If it doesn't stall, it will come back up to 500 RPMs, but does not hold it well, fluctuating quite a bit, and if left in gear long enough at idle, it will most likely stall. Increasing the neutral idle speed will decrease my chances of it stalling, but then it is just too fast. I have adjusted the idling mixture screws, in/out and every which way.

They both have Rochester 4ME carbs.

Any suggestions on how to fine tune this engine to get it to idle better?

-Scott

Re: AQ260A idle question

I've been on vacation and away from the boat. I'm planning on taking a look at this idle problem this weekend. Does anyone have any suggestions on where to start looking to steady out the low speed idle?
Thanks

Re: AQ260A idle question

I suppose the idle mixture screws are the place to start. I think those engines should be about 600-650 in gear. Maybe 700-750 in nuetral.

I was having idling trouble last year. Had the carb gone though, idles good now.

As long as you know the fuel, filters etc are good, as well as all tune up parts, timing, dwell, ect., ect., didn't mention points, condenser. You have electronid ignition?

If all else is good, have the carb done. I had mine done by an old timer mechanic for $75 + kit. I thought that was a steal.

Let us know what happens. Good luck to you!!

Re: AQ260A idle question

sounds like a vaccum leak do the rpms change when you turn the mixure screws

Re: AQ260A idle question

i'd agree to the vacuum leak, or possibly choke adjustment

Re: AQ260A idle question

yep you can also put a vacuum guage on it and set the mixture screws at he highest point of vacuum