Cliff's Quadrajet Parts and Rebuild Kits

Quadrajet Problem Solving => Diagnose a Quadrajet carburetor problem => Topic started by: Mr.Pontiac on July 08, 2013, 02:19:04 PM

Title: 7027263 carb. no responce on idle mixture screws??
Post by: Mr.Pontiac on July 08, 2013, 02:19:04 PM

Rebuilt with Cliff,s parts, starts right up but no responce with idle screws at all, i did notice baseplate has a very small idle bypass hole .030, should i open it up to at least .070?????First recipe .036 idle tubes channels set at .046, .130 inlet seat.Cut one ring off each spring on idle screws so as not to bind so thats not the issue.

Title: Re: 7027263 carb. no responce on idle mixture screws??
Post by: Cliff Ruggles on July 09, 2013, 04:10:08 AM

Engine size, compression ratio, cam specs?....Cliff

Title: Re: 7027263 carb. no responce on idle mixture screws??
Post by: Mr.Pontiac on July 09, 2013, 05:30:30 PM

All stock 400 motor, wt stock cam and running factory daul exhaust, stock point distrib.

Title: Re: 7027263 carb. no responce on idle mixture screws??
Post by: Cliff Ruggles on July 10, 2013, 04:05:43 AM

The 7027263 should have plenty of idle fuel for the stock engine with .036" idle tubes.  Are the idle airbleeds still the stock sizes?.....Cliff

Title: Re: 7027263 carb. no responce on idle mixture screws??
Post by: Mr.Pontiac on July 10, 2013, 12:35:43 PM

idle air bleeds airhorn, are a little big at .070 book calls for .055 holes under idle screws same .070 and base plate hole bypass is very small .030. Going to see if springs are coil binding, did not cut anything off them.

Title: Re: 7027263 carb. no responce on idle mixture screws??
Post by: Mr.Pontiac on July 12, 2013, 10:31:16 AM

Sure could use some help on this one Cliff!!

Title: Re: 7027263 carb. no responce on idle mixture screws??
Post by: Mr.Pontiac on July 13, 2013, 06:26:19 AM

Quote from: Mr.Pontiac on July 10, 2013, 12:35:43 PM

idle air bleeds airhorn, are  .055 holes under idle screws same .070 and base plate hole bypass is very small .030. Going to see if springs are coil binding, did not cut anything off them.

Title: Re: 7027263 carb. no responce on idle mixture screws??
Post by: Mr.Pontiac on July 13, 2013, 06:27:24 AM

Quote from: Mr.Pontiac on July 10, 2013, 12:35:43 PM

idle air bleeds airhorn,  .055 holes under idle screws same .070 and base plate hole bypass is very small .030. Going to see if springs are coil binding, did not cut anything off them.

Title: Re: 7027263 carb. no responce on idle mixture screws??
Post by: Cliff Ruggles on July 19, 2013, 03:36:07 AM

The 7027263 should have very small upper idle airbleeds in the airhorn, closer to .040" than .070".

There is no idle bypass air in the baseplate on those units....Cliff