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Carb linkage ratio

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Old 03-16-2017 | 07:12 PM
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Default Carb linkage ratio

I just received my new Quick Fuel carbs and they can be set up with different throttle ratios for the primary and secondary. The choices are 60%, 40% and 1:1. They are set up that the primaries will be open 40% when the secondaries open. What are your thoughts on this? Should I leave this stock or set it up 1:1? I wouldn't think the 60% linkage would be of use.

Last edited by endeavour32; 03-16-2017 at 07:48 PM.
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Old 03-16-2017 | 07:25 PM
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Mike I think I would start with box settings at 40% so your not lean at cruising rpm etc. Once you install AFR Wideband o2 sensors let that be the determine factor.
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Old 03-16-2017 | 07:32 PM
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Another thought would be to fatten up your primaries 2 or 3 jet sizes and go the 50% linkage but that will like throw off your AFR's at lower rpm and all the way through. I'm not holding a holley in my hand at the moment but sure seems most their DPs are about 40%. Get some bungs installed before you even run it next?

Last edited by getrdunn; 03-16-2017 at 07:51 PM. Reason: Deleted info misinterpreted
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Old 03-16-2017 | 07:47 PM
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Set up stock, the primary are open 40% when the secondaries open. I agree that seems soon, there is also a 60% linkage, which seems to me is how how all of my Holleys have been set up.

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Old 03-16-2017 | 07:49 PM
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iN THE PAST HAVE SET UP SECONDARY OPENING point to begin just past were I determined a good low to mid cruse speed often around half throttle at the most helped with economy. I consider a cruse speed to be 1/3 to 2/3 throttle, 3/4 throttle or more high speed. All needs to be determined by running the boat.
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Old 03-16-2017 | 08:50 PM
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I'm gonna pull off his little linkage anyway when he's got his head turned. A 2 barrel carb is more than enough. Hah. Congrats on the new carbs mike. I'd like to switch over to those QF's eventually. Just getting on the water for now I will be satisfied.
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Old 03-16-2017 | 09:08 PM
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Originally Posted by getrdunn
I'm gonna pull off his little linkage anyway when he's got his head turned. A 2 barrel carb is more than enough. Hah. Congrats on the new carbs mike. I'd like to switch over to those QF's eventually. Just getting on the water for now I will be satisfied.
I may ask to come over and do some port matching on my exhaust this weekend, If I'm going to be running 2 barrels, I'm going to need all the help I can get!
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Old 03-17-2017 | 09:24 AM
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Mike, I would try the stock setting first, and like John said, see how the afr's look. 1:1 carbs, usually will have the primary, and secondary set up the same way, meaning jets/pv etc. Which model carb did you get?
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Old 03-17-2017 | 12:34 PM
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just to throw it out there, out of at least a half dozen Dominators I have seen they have been set up 1:1 and nearly square front to rear with PV in the rear only
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Old 03-17-2017 | 02:36 PM
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Originally Posted by MILD THUNDER
Mike, I would try the stock setting first, and like John said, see how the afr's look. 1:1 carbs, usually will have the primary, and secondary set up the same way, meaning jets/pv etc. Which model carb did you get?
I bought the Q-950's. I thought about the 1050's but I don't think I need that much carb. If it turns out I need more, I'll just swap out the main bodies for 1050's.
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