Cliff's Quadrajet Parts and Rebuild Kits

General Category => Quadrajet Carb Talk and Tips => Topic started by: PMD1969 on March 10, 2013, 11:07:44 AM

Title: Busted air/fuel screw stuck
Post by: PMD1969 on March 10, 2013, 11:07:44 AM
When taking apart a Qjet base one of the screws popped the head off.  There is just enough left for a small pair of pliers to grab what is sticking out.  I know if I do this it will just tearing up the remaining amount of visible screw post and it won't come out.

What would be the best method to removing it?
Title: Re: Busted air/fuel screw stuck
Post by: 429bbf on March 10, 2013, 08:10:37 PM
do you have access to a small mig welder? if you do lay a washer over the little piece that is sticking out weld the screw to the washer and then tack a nut to the washer to screw it out . also when its hot from welding put some canning wax on the hot screw . the heat will pull the wax into the threads and it will screw right out.if you dont have a welder you may have to drill it. just make sure you get it perfectly centered.that way you can drill it completly out and chase the pieces out with a tap.hope this helps
Title: Re: Busted air/fuel screw stuck
Post by: PMD1969 on March 11, 2013, 11:09:59 AM
do you have access to a small mig welder? if you do lay a washer over the little piece that is sticking out weld the screw to the washer and then tack a nut to the washer to screw it out . also when its hot from welding put some canning wax on the hot screw . the heat will pull the wax into the threads and it will screw right out.if you dont have a welder you may have to drill it. just make sure you get it perfectly centered.that way you can drill it completly out and chase the pieces out with a tap.hope this helps

Unfortunately I do not have a welder.  The base plate has been cleaned and now I am going to check and see if a mix of ATF/Acetone will be safe enough on the plate material to then try and loosen the screw.  I have only two ways of getting it out.  One is using a Dremel to slice a notch and use a Flathead or clamp on and pray.
Title: Re: Busted air/fuel screw stuck
Post by: Ethan1 on March 11, 2013, 11:44:29 AM
 I hope your able to get it out of there. Please keep us posted!
Title: Re: Busted air/fuel screw stuck
Post by: PMD1969 on March 19, 2013, 11:40:56 AM
Still stuck.  I have let it soak with PB Blaster for days and then tried to turn it out with a pair of needle nose pliers.  Of course this screw is stuck in the hole where there is little space to grab it with  ::).  I am going to try ATF/Acetone after this.
Title: Re: Busted air/fuel screw stuck
Post by: 429bbf on March 19, 2013, 07:25:21 PM
try and warm up the screw with a small torch. apply canning wax and let it cool. it will come out unless someone has cross threaded it.if thats the case (i dont know how handy you are or what tools you have access to) i fixed one by first setting the fuel bowl back on. the i took a drill bit (just small enough to fit down the hole ) that way it will center the hole perfect. then i drilled it out and tapped it to 3/8 because i had a brass 3/8 bolt. i lock tited the bolt and made it flush on both sides. i put the fuel bowl back on ,got myself a new center, drilled and tapped back to the proper size. id show a picture but its running on my 79 ford 460.hope this helps.
Title: Re: Busted air/fuel screw stuck
Post by: 429bbf on March 19, 2013, 07:28:36 PM
sorry about that last post . i was talking about a back busted screw in the base plate.
Title: Re: Busted air/fuel screw stuck
Post by: PMD1969 on March 29, 2013, 08:56:31 PM
Alright.  After repeated attempts the screw is still stuck.  Where can I find a base plate to replace it so I can move forward?
Title: Re: Busted air/fuel screw stuck
Post by: billy 2 on March 30, 2013, 12:24:34 PM
Try going to your local machine shop.  They should be able to take the screw out.  If not, they will drill it and could probably put a heli coil in.  billy 2
Title: Re: Busted air/fuel screw stuck
Post by: 429bbf on March 30, 2013, 09:21:45 PM
exactly whick screw broke off( in the fuel bowl or in the throttle shaft?
Title: Re: Busted air/fuel screw stuck
Post by: PMD1969 on March 31, 2013, 01:34:04 PM
Try going to your local machine shop.  They should be able to take the screw out.  If not, they will drill it and could probably put a heli coil in.  billy 2

Although I do need to find a machine shop for other work I was oping to see if I could acquire a base plate cheaper and quicker than finding a shop and paying to get it doe.  Since I live in Soccer Mommy town there are few if any shops like this aroud.
Title: Re: Busted air/fuel screw stuck
Post by: PMD1969 on March 31, 2013, 01:35:00 PM
exactly whick screw broke off( in the fuel bowl or in the throttle shaft?

Which ever one is one the left that is the toughest one to get too.
Title: Re: Busted air/fuel screw stuck
Post by: Ethan1 on March 31, 2013, 02:15:55 PM
Although I do need to find a machine shop for other work I was oping to see if I could acquire a base plate cheaper and quicker than finding a shop and paying to get it doe.  Since I live in Soccer Mommy town there are few if any shops like this aroud.

 What carb number are we talking about here?
Title: Re: Busted air/fuel screw stuck
Post by: PMD1969 on April 01, 2013, 12:15:39 PM
What carb number are we talking about here?

7028260   its an automatic carb going on a manual car.  If I could find a manual base plate I wouldn't have to block off the two auto ports.  Either way it will work.
Title: Re: Busted air/fuel screw stuck
Post by: Ethan1 on April 01, 2013, 01:32:19 PM
7028260   its an automatic carb going on a manual car.  If I could find a manual base plate I wouldn't have to block off the two auto ports.  Either way it will work.

 Keep your eye out for base plate number 7035842 for the 7028260 and 7035558 for the 7028261.
Title: Re: Busted air/fuel screw stuck
Post by: 429bbf on April 01, 2013, 05:16:09 PM
pmd send the base plate to me and ill take it out (free of charge ) i like a challenge once in a while. zip 82718
Title: Re: Busted air/fuel screw stuck
Post by: Shark Racer on April 01, 2013, 08:40:11 PM
Are there any good photo documents of how these early APT setups work? I'd love to see one...
Title: Re: Busted air/fuel screw stuck
Post by: PMD1969 on April 15, 2013, 03:28:46 PM
I have yet to put any heat on the screw and base plate.  I have a MAPP torch I can use.  Anyone know how much heat the base plate can take.  I really do not want to FUBAR it up.

Marc
Title: Re: Busted air/fuel screw stuck
Post by: 429bbf on April 15, 2013, 08:34:56 PM
marc id heat it up to at least 150 -200 . some of that loctite doesnt like to let go.heat the top and bottom evenly and dont hold it on to long.i put mine in 180 degree water and it didnt come loose so i took the torch and go it hotter im guessing close to 250 once i got it to move a little i melted wax on it and it came right out.
Title: Re: Busted air/fuel screw stuck
Post by: 429bbf on April 15, 2013, 08:43:52 PM
shark answer to your question . my camera broke or id take photos. best way to explain it is like this. have you ever mounted anything on a sheet rock wall?you drill a hole and insert a plastic piece and then you put in the screw and the screw spreads the plastic open so it wont pull out.works the same way. the screw spreads a steel  (y )looking piece which spreads and raises the power valve which has a little rod protruding out the bottom of it.ill post some pics when i get my camera fixed.fwiw
Title: Re: Busted air/fuel screw stuck
Post by: Shark Racer on April 15, 2013, 09:10:29 PM
Neat. Looking forward to it.

Thanks for the explanation!

Do all the 4Ms have this setup or just a few?
Title: Re: Busted air/fuel screw stuck
Post by: PMD1969 on May 27, 2013, 08:48:31 AM
Well... it hs been a while and I have tried putting some MAPP heat to the affect screw.  No dice.  I heated it up and run some wax in it.  Then tried to clean it out reheat and put some PB in overnight.  Then tried to cut slot down the middle and used a small flathead to turn it.  Broke that.