I run 1:1 linkage on my dual carb setup, and it runs fine and idles clean. I think progressive linkages are adding complexity that you don't need. Just my 2 cents.
Thanks for this, I am just about to install a dual quad, 1:1 setup on my 408, and did exactly that. I jetted carbs down thinking there would be more fuel. I will set them back to standard setting for initial trial.When you double the available throttle bore area you effectively cut in half the signal to all of the fuel supply. You went leaner initially with rods and jets and you should have gone richer. Common misconception that a bigger carb (or multiple carbs) will drown an engine. It’s exactly the opposite. Make changes based on observations not on assumptions. Read your plugs.
Jetting (and all fuel/timing adjustments for that matter) should always be made because you observed something. Find a problem, Make a change, observe the result, repeat. You dont ever want to guess or assume.Thanks for this, I am just about to install a dual quad, 1:1 setup on my 408, and did exactly that. I jetted carbs down thinking there would be more fuel. I will set them back to standard setting for initial trial.
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Agree, but when you are doing something new, you need a baseline with which to start. Can't observe, until you try something. Seems my intuition was wrong on baseline settings.Jetting (and all fuel/timing adjustments for that matter) should always be made because you observed something. Find a problem, Make a change, observe the result, repeat. You dont ever want to guess or assume.
Agree, but when you are doing something new, you need a baseline with which to start. Can't observe, until you try something. Seems my intuition was wrong on baseline settings.
I have two AVS2 1906 carbs, which are 650's, I then put boosters in the primary sides out of 1902's, which are 500's. These boosters knocked 100cfm out of each carb, giving me 550's with large secondaries like a Thermoquad somewhat. If I need more, I will put in the 650 primary boosters, this way I'm not pigeon holed on maxed out 500 cfm carbs. Any advise or comments on initial setup most welcomed and appreciated. If the OP feels I've hijacked his post, apologies.
You don’t need to mess with the secondary rods/jetting at all right now. Leave those for when you get to wot tuning. Just make sure the secondary bores are closed. Then work on getting the primary right. You are popping through the intake because you are lean. You need more fuel.
Stop trying to run it and tune anything until you have all the vacuum leaks plugged. It won’t do a damn thing. And whoever told you to run the mixture screws all the way in is wrong. Bottom them all lightly and then turn them all out 1 turn as a starting point. Closing the choke on the secondary carb won’t do anything if you have the curb idle screw backed all the way out either. You’re getting there.
Got it idling decent, still seems really rich, or blow by?
At idle, the "rods" are not used, all idle fuel is controlled by the idle mixture screws.