New (rebuilt carb) - less power? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

ohenryoh · 08-22-2007, 01:25 PM

I just put a rebuilt carb on my 72. It is a Quadrajet, I switched to Electronic choke (which I love) but I seem to have lossed top end speed? My old carb made my truck one cold starting son of a buck but once it was running the truck had plent of juice. The new fires up great and from O - 60 it runs really strong but I seem to top off at 70-75 mph. Any ideas? Do I have to reset my timing?

**WorkinLonghorn** · 08-22-2007, 01:42 PM

Check to make sure your secondaries are opening,Sometimes if you screw-up the assembling of the carb they don't open right. If they are opening then I'd make sure you set the float level correctly.You changed or blew-out the little fuel filter right? Those are the first things that come to mind,and no,you shouldn't have to change the timing after card rebuild,but it wouldn't hurt to check it.
Also make sure the choke is fully opened up after warm-up.

67ChevyRedneck · 08-22-2007, 01:43 PM

Do you mean the pedal is hitting the floor at 70? You may need to adjust your throttle cable or rod?

Or do you mean after 70 it has no more power? Maybe the jets and settings?

ohenryoh · 08-22-2007, 02:14 PM

Its screaming at 75 and the pedal is on the ground. Seems like the the secondaries are opening up.

08-22-2007, 01:25 PM	#1
ohenryoh Registered User Join Date: Aug 2007 Location: Santa Fe, New Mexico Posts: 8	New (rebuilt carb) - less power? I just put a rebuilt carb on my 72. It is a Quadrajet, I switched to Electronic choke (which I love) but I seem to have lossed top end speed? My old carb made my truck one cold starting son of a buck but once it was running the truck had plent of juice. The new fires up great and from O - 60 it runs really strong but I seem to top off at 70-75 mph. Any ideas? Do I have to reset my timing?

08-22-2007, 01:42 PM	#2
WorkinLonghorn Senior Member Join Date: Dec 2006 Location: Studio City, Calif. Posts: 2,861	Re: New (rebuilt carb) - less power? Check to make sure your secondaries are opening,Sometimes if you screw-up the assembling of the carb they don't open right. If they are opening then I'd make sure you set the float level correctly.You changed or blew-out the little fuel filter right? Those are the first things that come to mind,and no,you shouldn't have to change the timing after card rebuild,but it wouldn't hurt to check it. Also make sure the choke is fully opened up after warm-up. __________________ '69 GMC C2500 Custom Camper, 8 1/2' bed, New GM 350, NP 435 Close Ratio 4spd. Trans., 3.73 Dana-60 open.Camper and Trailer wiring, PS, PB, AC, tach , three gas tanks, 2nd owner, Work-Truck supreme. Best $300 I ever spent. Last edited by WorkinLonghorn; 08-22-2007 at 01:43 PM.

08-22-2007, 01:43 PM	#3
67ChevyRedneck Hittin E-Z Street on Mud Tires Join Date: Nov 2004 Location: Greenville, SC Posts: 23,090	Re: New (rebuilt carb) - less power? Do you mean the pedal is hitting the floor at 70? You may need to adjust your throttle cable or rod? Or do you mean after 70 it has no more power? Maybe the jets and settings? __________________ Jesse James 1967 C10 SWB Stepside: 350/700R4/3.73 1965 Ford Mustang: 289/T5-5spd/3.25 Trac-Loc 1968 Pontiac Firebird: Project Fire Chicken! 2015 Silverado Double Cab 5.3L Z71 2001 Jeep Wrangler Sport 4.0L 5spd 2020 Chevrolet Equinox Premium 2.0L Turbo 2011 Mustang V6 ~ Wife's ride American Born, Country by the Grace of God 1967 CST Shop Truck Rebuild! My 1967 C-10 Build Thread My Vintage Air A/C Install Project "On a Dime" Trying my hand at Home Renovation! 1965 Mustang Modifications!

08-22-2007, 02:14 PM	#4
ohenryoh Registered User Join Date: Aug 2007 Location: Santa Fe, New Mexico Posts: 8	Re: New (rebuilt carb) - less power? Its screaming at 75 and the pedal is on the ground. Seems like the the secondaries are opening up.



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