solex carb setup volvo penta aq151c/sp-a

[craigk]

Howdy....... anyone out there know the best way to set up the (dual)solex 44 pai downdraught carb? My clymer and volvo manual show two different methods and limited detail. ex.- is the idle jet supposed to be seated? The manual says to seat the idle mixture screw, then back it out so many turns. Is that all the adjustment you do with that screw? Just wondering if someone has any tips or tricks. Thanks

 

[Don S]

Re: solex carb setup volvo penta aq151c/sp-a

Loose the Clymer manual, and go by the Volvo manual.<br />The "turns out" you mention are only a preliminary setting. After you get the engine running you have to syncronize the carbs so they are both doing the same thing. You can get syncronizers for the carbs, or if you are very good at hearing what the carb sounds like, you can do it by ear.

 

[craigk]

Re: solex carb setup volvo penta aq151c/sp-a

Hey Don! Well I backed out the idle mix screws 8 turns as per the Volvo manual( the clymer says 1-1/4?) , and backed out the idle speed screws 1 turn as per the manual. Then, adjusted each idle speed screw equal amounts(not much) to get to 900 rpm. The idle hovers around 900 +or-50. The volvo manual doesn't say anything beyond that. I don't have a uni-syn. I could tinker more, if you think I could pull it off <br /><br />Thanks for the input

 

[Don S]

Re: solex carb setup volvo penta aq151c/sp-a

The Volvo manuals were designed for Volvo Techs and assumed they knew how to adjust the carbs with the engine running. Not knowing what vintage carbs you have, here is the best I can give you from the latest 151 manual.<br /><br />

<br /><br />

 

[craigk]

Re: solex carb setup volvo penta aq151c/sp-a

I've got the late version - my manual illustrates the same. I guess it is possible to sync the carbs without using a uni-syn? Do you think it is normal for the rpm to jump plus or minus 50 at 900 rpm?

 

[Don S]

Re: solex carb setup volvo penta aq151c/sp-a

No, but carb adjustment is only part of the whole picture.

 

[Weirdwalt]

Re: solex carb setup volvo penta aq151c/sp-a

I adjust them by sending the customer to a different shop. The problem with those is even though you adjust them correctly you end up married to them.

 

[Reel Poor]

Re: solex carb setup volvo penta aq151c/sp-a

Originally posted by Don S:<br /> or if you are very good at hearing what the carb sounds like, you can do it by ear.

One way I have learned to listen to these dual carbs is....Get yourself a length of heater hose...While holding the hose to your ear and "to" (not down in as this will interrupt air flow) the throat of the carb and listening closely (back and forth) you can identify subtle differences in the sound that the air and fuel flow makes as it is sucked in by the engine. Then adjust to harmonize/syncronize.