Author Topic: Drag car running 17056240 carb. but i have a issue  (Read 3407 times)

Offline Mr.Pontiac

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Drag car running 17056240 carb. but i have a issue
« on: September 26, 2018, 12:49:20 PM »
This carb. has gotten me steady 11.90,s and comes on like a animal, no hesitation or bog i am running no power piston no primary rods and using 65 jets. Main air bleed in air horn .070 running .135 needle and seat. Pulled idle tubes set them at .038 idle down at .052. Problem is i have no control at both air and fuel mixture screws. Should i open holes behind them to say .080?? or is it something else causing my issues,

Offline 77cruiser

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Re: Drag car running 17056240 carb. but i have a issue
« Reply #1 on: September 26, 2018, 05:28:55 PM »
How much vacuum do you have at idle?
Jim

Offline qjetsrule

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Re: Drag car running 17056240 carb. but i have a issue
« Reply #2 on: October 06, 2018, 09:29:51 PM »
Where is your throttle blade in relation to the transfer slot. With a big cam you may be idling off the main circuit. Is there fuel dripping out of the primary nozzles when idling? To check for proper idle/transfer throttle blade position it requires removing the carb and looking from underneath. If too much transfer slot is exposed you may have to increase bypass air or maybe increase discharge hole diameter as you suggested.

Offline Mr.Pontiac

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Re: Drag car running 17056240 carb. but i have a issue
« Reply #3 on: October 15, 2018, 12:18:41 PM »
Removed base plate last nite, Both idle mixture screw holes and Bypass are sitting at .104

Offline Mr.Pontiac

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Re: Drag car running 17056240 carb. but i have a issue
« Reply #4 on: October 15, 2018, 05:22:09 PM »
Forgot to mention in last reply, at .050 Duration is 242 on exhaust 236 on intake

Offline 77cruiser

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Re: Drag car running 17056240 carb. but i have a issue
« Reply #5 on: October 15, 2018, 07:33:03 PM »
How much initial timing do you have?
Jim

Offline Mr.Pontiac

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Re: Drag car running 17056240 carb. but i have a issue
« Reply #6 on: October 16, 2018, 02:40:51 PM »
MSD distrib. is fully locked out at 3,000 rpms and timing set at 34 degreee,s

Offline 77cruiser

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Re: Drag car running 17056240 carb. but i have a issue
« Reply #7 on: October 17, 2018, 10:27:53 AM »
Is it locked or does it max out at 3000? What's the timing at idle?
Jim

Offline Mr.Pontiac

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Re: Drag car running 17056240 carb. but i have a issue
« Reply #8 on: October 18, 2018, 12:00:47 PM »
Please forgive me but this has not anything to do with my carb. issues

Offline 77cruiser

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Re: Drag car running 17056240 carb. but i have a issue
« Reply #9 on: October 18, 2018, 12:10:33 PM »
If the throttle plates are open too far it does. If you add timing at idle you can close the throttle.
Jim

Offline Mr.Pontiac

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Re: Drag car running 17056240 carb. but i have a issue
« Reply #10 on: October 20, 2018, 11:48:25 AM »
Sorry it took so long , but i have a little bit of time today to check things out so here go,s, at idle 26 degree,s ,  with a vacum gauge connected i am fluxuating from 8 to 10 psi very fast.At 32 degree,s
at 3,000 right now i cannot throw any more timing in motor or it cranks very slowly with new battery.This is telling me a ignition problem of some kind i believe, plugs gapped at .032. Motor sounds great past 2,000 if i troump down on it.

Offline 77cruiser

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Re: Drag car running 17056240 carb. but i have a issue
« Reply #11 on: October 20, 2018, 01:05:14 PM »
You could open your idle air bypass some but then you'd probably have give some more fuel, idle tubes & DCR.
Jim

Offline Mr.Pontiac

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Re: Drag car running 17056240 carb. but i have a issue
« Reply #12 on: October 20, 2018, 03:33:22 PM »
Its almost like i am into idle circuit. I tryed to run Cliffs 3 rd reciepe but did not open idle down channels at all. Still factory .052. His book suggests .059 to .064. Plugs where new and all where carboned up after 4 minute running at idle.

Offline Mr.Pontiac

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Re: Drag car running 17056240 carb. but i have a issue
« Reply #13 on: October 20, 2018, 06:41:46 PM »
I took off top & opening idle down restrictions from .052 to .062, ill try it tommarrow.

Offline Mr.Pontiac

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Re: Drag car running 17056240 carb. but i have a issue
« Reply #14 on: October 21, 2018, 10:12:35 AM »
Appreciate all the help i am getting, Hay, Cliff what do you think??