Re: Quadra-jet idle mixing screws
Here is how I adjust them.
If you are planning on doing hole shots or pulling people and want to get up on plane as fast as you can. follow this procedure.
1 get engine up to normal operating temp making sure that the choke is open full.
2 Turn you air mixture screws all the way in till they just bottom out and turn them out again 2 turns.
3 adjust your idle to around 600 to 700 rpm, or as low and stable as you can get it.
4 You can do this by ear,vacuum gauge or with a tach.
Turn your air mixture screws out until you start to here or see (tach or vacuum gauge) the engine rev just a little and just when it starts to bog down a little turn in until max RPM is achieved. Do this with both needles one at a time.
If you are looking for better fuel economy and are just spending your days cruising around and not at WOT all the time follow the first 3 steps accept this time turn your needles in till the engine revs a bit and the starts to bog and turn out till you are at maximum RPM.
5 After your needles are set return the idle of your boat to around 700-750 RPM
The reasoning on this is just that the mixture curve is a little small but you can choose which end you want to run at. For hole shots you want to be at the rich end just for that little bit of extra fuel before the carb switches to the primary circuit. And for cruising you can run a little on the lean side as not to waste the extra fuel dumping at idle it also dosen't carbon up the plugs as fast.
