Cliff's Quadrajet Parts and Rebuild Kits

Quadrajet Problem Solving => Diagnose a Quadrajet carburetor problem => Topic started by: 65malibu on June 16, 2025, 02:25:52 PM

Title: 17084226 tip in
Post by: 65malibu on June 16, 2025, 02:25:52 PM

I was trying to zero in my part throttle today and did the tip in. With 74 jets and Cliffs 50M rods, I started at 3.5 turns out on the APT screw. The engine rpm finally picked up at 1 turn out. Is that an indication that I should go down to 72 jets or will it be ok? With the screw only out 1 turn, where does that put the taper on the needle in relationship to the jet?

Title: Re: 17084226 tip in
Post by: Kenth on June 18, 2025, 12:47:10 AM

At 1 turn they are as low as they can be.
The APT starts rising the piston/rods at 2 turns up from bottom.

Title: Re: 17084226 tip in
Post by: 65malibu on June 18, 2025, 04:47:46 AM

I did check when the needle hanger starts to move when I had it apart and the pin starts to make contact around 1 1/2 turns from the bottom.
Should I go down on the jet size to bring the needles up more into the taper?

Title: Re: 17084226 tip in
Post by: Kenth on June 18, 2025, 01:20:27 PM

It´s the result with tip-in that counts and with a slight rpm pick-up with the APT 1 turn up and no driving issues i would say it´s good as is.

Title: Re: 17084226 tip in
Post by: quadrajam on June 18, 2025, 02:57:53 PM

I agree with Kenth. Should be good.

QJ