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Discussion Starter · #1 ·
I put in my new Holley HP 750 with mechanical secondaries, the gas pedal feels good when the primaries are opening, but as soon as the secondaries are opening the pedal requires a ton of effort. Any help?

Eric
 

· FFCobra Fanatic
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First thing to check is to make sure that you are not stretching the return spring past its limits. If you are using a cable, (and you should be) check it for lubrication and make sure it isnt binding.
 

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Disconnect the linkage and work the carb by hand. Is it still binding? If so then your throttle plates may be hitting something. If not then it is somewhere in the rest of the system.

Mike

[ December 09, 2002, 02:58 PM: Message edited by: mikiec ]
 

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Eric,
I would like to know what you find, I have a almost identical setup as yours in progress.

Mike
 

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Eric,

My Speed Demon, with mechanical secondaries, also gets stiffer when the secondaries start to open, but only a little bit. This should be normal, because there is a second spring for the secondaries.

On a side note: With 2 return springs, per NHRA rules, my stainless braided Lokar cable was compliant, so I kept loosing WOT. I switched to the black Lokar cable, and it fixed the problem. You may run into this problem with your new carb.

craig
VPM
 

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Wouldn't the mech secondaries have more resistance than vacuum secondaries?I remember doing a carb swap before and noticing the same thing.Or is it possibly the plates sticking/rubbing?
 

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What you should also check is the physical aspect of the pedal. The lever action of pedals is to minimize the force necessary to control gas/brake/clutch etc. A lever is in its ideal position for the mechanical advantage when it is perpendicular to the applying and resisting forces. However, when you press the pedal the lever is arcing and you are losing more of this advantage as it arcs. Check your pedal and see if the upper part of the pedal (above the pivot point), is way forward (closer to you)when you reach the secondaries. You may have to reposition the pedal at a different angle to start pulling sooner. In other words, the bottom mount needs to come outward and/or the point which the cable mounts may need to be raised. I am not familiar with that pedal setup but I figured this MAY help if you are at a dead end. Good luck
 

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Discussion Starter · #15 ·
It has to do with the bracket i believe the throttle cable goes in, cause it apears to bend and shift so i will replace that. When i remove the cable and open/close carb with my hand, it feels good.

Congrats on the blower, you will love it, feel free to drill me with anything!

Eric
 

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Eric,
I think I'm allergic to the polish on it. everytime I look at it I giggle.

mike

I bought a BIGGS also, we should go down together or drive in glory together...
 

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I've been trading emails with Lynn and I did put your name in with your setup. I can't wait to get it. I'll be at DVSFIII, see you there!

Mike
 
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