Harold, old set of guitar strings work well also. The heavier “wound” strings are great because the center wire is very thin and the wound portion cleans well because of the windings.
32:25 had my Rochester carb assembled at the shop because I didn't have time. Upon installation, I noticed problems getting the car off of fast idle. Couldn't get the primaries to close. Upon looking closer, the fast idle plate lever was ON TOP of the fast idle cam. Should be underneath as this segment shows! I spent a long time trying to figure this out and this video helped confirm that. Appreciate it man. Keep up the good work.
It is ridiculous how satisfying it is to see how clean that bead blasting made everything.. looks like it just rolled out of the cast yesterday. Plus them polished plates and coating.. mmm. Sad all that is such an investment, but good on ya man.
Hey Harold, much thanks. I have this carb in a mid 80's RV that had been sitting. When the choke went off, the engine would not idle. Following your instructions, I removed the horn, carb cleaned and wired all of the orifices, paying particular attention to those two idle ports. The carb was actually pretty clean so I put it back together, success!
Glade these videos helped. I get a fair amount of work from these videos but I get the most satisfaction when you guys tackle this stuff your self and have success. TH-cam is such a great forum for people to share there skills.
Harold, you do things the way I like to them. Everything like new! Best videos on Quadrajet carburetors I have seen. Only suggestion I would have is to get yourself a Bass Pro box with compartments to put your parts in. Would save you some time. Ha!
Harold this has got to be the best instructional video ever on the old Rochester Q-jet carbs ❤ We used to through them out back in the 70s and put the holly on are big block Chevys , now I know if we had you around the Q-jets would still be on the cars 😂. I just got a 1969 corvette 427/390 and it’s all matching numbers right down to the carburetor which I have all apart after watching your video #1. Just wondering do you do this as a job ? If so how much to do one , I just love all the plating which I can’t do.
Hi Walter Yes I do Carburetor Restoration's. Quadrajets are $340.00 + Shipping back to you. Any missing parts or in/op choke pull off will be extra and quoted. chucknorbid@gmail.com Thanks Harold
Great video a lot of good information. I have a question you might be able to answer. I have a 1972 cadillac hearse with the 472. Ive rebuilt my carb but must have missed something. Question when in park car will idle nice and smooth but in gear sitting at a light or stop sign car has a rough idle to the point of a drop in idle to where it wants to stall and then come back up and will do it the whole time but will take off fine and run right. What could be causing this do you have any suggestions. Thank you
I soaked my QJ in a 5 gallon bucket of chem dip for 7 hours and still has some gunk......also, is there a pretty big well on the bottom of the airhorn that does nothing? I can't see any holes in that space.
I've always loved q jets over squarebores they are awsome i had good luck with all the gms and quads now i need one that used to be a dime a dozen and can't find one I need one for a 305 in a chevy truck im running one off a pontiac and it runs but barely well maybe more than barely lol
Great video! The most detailed and knowledgeable I’ve seen. Q: my new gasket has a hole missing. I run a bog standard 350 auto daily driver/cruiser. Can you share what affect this gasket may have if any? Can I send you a photo to show which hole? 🙏 Car seems to run fine (first run) TIA
Chevrolet used side inlet. Olds/Buick/Pontiac used front style. There were a few exceptions. Had to do with fuel line routing. Chevy did not have the room for the straight one. Also by using the straight fuel inlet they were able to use a 1" long fuel filter.
I have a Jet Performance built Q-jet that the driver's side idle screw won't screw in all the way. It was like that from Jet Performance so I called them about the problem. Their responded by sending me 2 new idle screws which of course didn't fix the problem. Can I run a tap through the driver's side idle screw hole and straighten out the threads? If I can what size tap is required?
Those are just for the secondary accelerator fuel . You don't want them to fill faster or you will be pulling fuel from them plus the secondary main system. They are just for the initial secondary operation so you don't get a secondary bog.
Great video ,but you never show the appication numbers or date code . I learned more now then I did back in the 70's 80;s. the reason why I'm getting back into this ,is I bought my a70 Monte SS 454 back in 1992, & I rebuilt the 7040200 EE carb back in 1996 .I took my car in for a tune up in 2016 . Now I took it out for a spin but had carb issues. I found out that my carb is not the 7040200 EE . It is from a 75 . so now I'm totally pissed about what has happened . So what I need to know is what my original carb should look like .Can you give any reference to what I should do to make it as close to original? I hate thieves and liers. I thank you for your professionalism and honesty.
Do a google search images for Rochester Quadrajet 7040200. It will come up with a lot of picks. Keep checking EBay they turn up now and then. Thanks Harold
@@backnine thank you for responding Harold . Now from what I have learned so far is that the 800 CFM came out after 1970 ,so I don't think the Ls-5 454 had one of those 800 CFM's unless it was something that wasn't published back then due to all the insurance and C.A.R.B .mandates. And as far as looking for another 7040200 EE carbs , then the next time I have to take it to another mechanic , what else is going to go missing? You see my dilemma? But I know already that I can trust you and the work you do because you are knowledgeable and you demonstrate your work . Thank you.
@@arnoldschmidt2753 Chevy never used the 800 CFM Carburetor. Pontiac had them on the Ram Air package. Olds/Buick/Cadillac used them I think around 73. Harold
@@backnine Thank you Again for responding . So that info confirms what I've been reading. Now you spoke about the bowl vent and hot engine compensator bi metal valve on the back of the main body . My7040200 EE had those . but I just can't just buy those 2 parts unless I have the correct body . The bowl vent is available but doesn't it work in tandem with the bi metal hot Idle compensater design ? Thanks again Sir.
When it gets hot (20+ mile drive) the carb acts like is starves for fuel and cannot run faster than an idle. Let it idle a little while and you can accelerate a second or two and then starve again. Any idea? If is getting good fuel supply and running with no fuel filter ( has a separate inline fuel filter outside of the carb). Could it be the float gets hot and floats too high (it ran fine for many years but has recently started doing this)
Sounds like a fuel supply problem. Fuel pump not putting out after it gets hot/Needle seat sticking. If the float was to high the engine would be flooding out.
@@backnine Is it possible for the float to sink when it gets warm? I will look at replacing the float, needle and seat. It has a new fuel pump that gets plenty of fuel to the carb inlet (tested by cranking engine with inlet tube disconnected and stuck into container to catch gas). THANKS!!!
@@backnine Even though my qjet is for my old motorhome I'd love my carb rebuilt to this level of care and detail... I've e-mailed you (first name Anthony). You're a true craftsman and your work here is beautiful
Hump side, but not on the hump itself. Regardless of where it goes on the flat parts on either side of the hump, it still operates the same. Its no so much the spring that's going to make a difference in filling/refilling correctly, that's the float's job. The float lifts up, and it lets the needle valve drop and start closing the fuel off, the float eventually rises and physically pushes down on the needle to shut off fuel completely. Regardless of where the spring is, as long as the float is lifting it out and the float can go all the way up to where it pushes the needle down, then it's fine (that's why there's a measurement spec for where the float height should. If it's too low, the float will top out against the air horn and the needle wouldn't close all the way. If it's too low, it'll shutoff the needle/valve prematurely and then engine will starve for fuel/lose power overall when trying to really getting into the throttle because the valve is closing too much too early.)
The first adjustment the carb was flooding, gas coming out the top, the next 4 adjustments on the float was not getting any gas. It would start with Starting fluid.
Hi Reed You probably have a bad needle seat assembly or you have crap logged in the seat area. Also the D clip (Float Pivot) that holds the float in has to be slightly above the body so the air horn pushes it in its seat. The tool I show on the video is just a depth gauge you can find on eBay. Also if you have a brass float it might be leaking and filling with fuel.Use the black solid float Harold.
Harold, Well this is where i feel really stupid, reset the float adjustment and was checking if the primary's were plugged nope, checked the accelerator pump and i was missing the spring underneath, Duhh. Thanks for your help
Harold rebuilt my 390 CFM Holley and it came out perfect, only adjustment I made was the idle. He’s the man.
How did you contact him for service?
Harold, old set of guitar strings work well also. The heavier “wound” strings are great because the center wire is very thin and the wound portion cleans well because of the windings.
this is a work of art...
Excellent video on explaining the ins and outs of the Q-jet. Thanks a lot.
32:25 had my Rochester carb assembled at the shop because I didn't have time. Upon installation, I noticed problems getting the car off of fast idle. Couldn't get the primaries to close. Upon looking closer, the fast idle plate lever was ON TOP of the fast idle cam. Should be underneath as this segment shows! I spent a long time trying to figure this out and this video helped confirm that. Appreciate it man. Keep up the good work.
Thank you so much for showing that you're a big help if I was around you I'd buy you a coffee lol
It is ridiculous how satisfying it is to see how clean that bead blasting made everything.. looks like it just rolled out of the cast yesterday. Plus them polished plates and coating.. mmm. Sad all that is such an investment, but good on ya man.
Hey Harold, much thanks. I have this carb in a mid 80's RV that had been sitting. When the choke went off, the engine would not idle. Following your instructions, I removed the horn, carb cleaned and wired all of the orifices, paying particular attention to those two idle ports. The carb was actually pretty clean so I put it back together, success!
Glade these videos helped. I get a fair amount of work from these videos but I get the most satisfaction when you guys tackle this stuff your self and have success. TH-cam is such a great forum for people to share there skills.
Harold, you do things the way I like to them. Everything like new! Best videos on Quadrajet carburetors I have seen. Only suggestion I would have is to get yourself a Bass Pro box with compartments to put your parts in. Would save you some time. Ha!
Harold this has got to be the best instructional video ever on the old Rochester Q-jet carbs ❤ We used to through them out back in the 70s and put the holly on are big block Chevys , now I know if we had you around the Q-jets would still be on the cars 😂. I just got a 1969 corvette 427/390 and it’s all matching numbers right down to the carburetor which I have all apart after watching your video #1. Just wondering do you do this as a job ? If so how much to do one , I just love all the plating which I can’t do.
Hi Walter
Yes I do Carburetor Restoration's.
Quadrajets are $340.00 + Shipping back to you.
Any missing parts or in/op choke pull off will be extra and quoted.
chucknorbid@gmail.com
Thanks Harold
Great video a lot of good information. I have a question you might be able to answer. I have a 1972 cadillac hearse with the 472. Ive rebuilt my carb but must have missed something. Question when in park car will idle nice and smooth but in gear sitting at a light or stop sign car has a rough idle to the point of a drop in idle to where it wants to stall and then come back up and will do it the whole time but will take off fine and run right. What could be causing this do you have any suggestions. Thank you
Do you have a video on platting and cleaning?
I'm wondering if you galvanize the base plate.
I soaked my QJ in a 5 gallon bucket of chem dip for 7 hours and still has some gunk......also, is there a pretty big well on the bottom of the airhorn that does nothing? I can't see any holes in that space.
Mechanic said my carb is dumping raw gas into engine, it occasioanly makes muffled poof or puff sounds out the tailpipe when iding ?
Can you go over existing welds with marine JB weld marine or do you have to drill and remove old compound
awesome job! Thanks for taking the time to explain all this, it is very appreciate ! I don't see how you blackened the screw?
Working on that Video.
I've always loved q jets over squarebores they are awsome i had good luck with all the gms and quads now i need one that used to be a dime a dozen and can't find one I need one for a 305 in a chevy truck im running one off a pontiac and it runs but barely well maybe more than barely lol
Great video! The most detailed and knowledgeable I’ve seen. Q: my new gasket has a hole missing. I run a bog standard 350 auto daily driver/cruiser. Can you share what affect this gasket may have if any? Can I send you a photo to show which hole? 🙏 Car seems to run fine (first run) TIA
chucknorbid@gmail.com
Excellent detailed video series!. Was there a reason the fuel inlet holes have some centered on body and some at a right angles? Older versions maybe?
Chevrolet used side inlet. Olds/Buick/Pontiac used front style. There were a few exceptions. Had to do with fuel line routing. Chevy did not have the room for the straight one. Also by using the straight fuel inlet they were able to use a 1" long fuel filter.
I have a Jet Performance built Q-jet that the driver's side idle screw won't screw in all the way. It was like that from Jet Performance so I called them about the problem. Their responded by sending me 2 new idle screws which of course didn't fix the problem. Can I run a tap through the driver's side idle screw hole and straighten out the threads? If I can what size tap is required?
8-32 Tap
Take the base off so you can blow the chips out.
Can a hole be drilled into it secondary fuel wells to let them fill up faster?
If they are slow to fill.
Those are just for the secondary accelerator fuel . You don't want them to fill faster or you will be pulling fuel from them plus the secondary main system. They are just for the initial secondary operation so you don't get a secondary bog.
Great video. Can I ask what was the cleaning product you used to clean the carb like that? Thanks!
First I degrease in Berrymans chem dip(5 gal pail). Then rinse in 5 gal simple green and water. then clear water. Dry and glass bead.
Hey Harold. I striped the filter threads in my carburetor bowl. Can I use a bowl that came off a manual carburetor?
Great video ,but you never show the appication numbers or date code . I learned more now then I did back in the 70's 80;s. the reason why I'm getting back into this ,is I bought my a70 Monte SS 454 back in 1992, & I rebuilt the 7040200 EE carb back in 1996 .I took my car in for a tune up in 2016 . Now I took it out for a spin but had carb issues. I found out that my carb is not the 7040200 EE . It is from a 75 . so now I'm totally pissed about what has happened . So what I need to know is what my original carb should look like .Can you give any reference to what I should do to make it as close to original? I hate thieves and liers. I thank you for your professionalism and honesty.
Do a google search images for Rochester Quadrajet 7040200. It will come up with a lot of picks.
Keep checking EBay they turn up now and then.
Thanks Harold
@@backnine thank you for responding Harold . Now from what I have learned so far is that the 800 CFM came out after 1970 ,so I don't think the Ls-5 454 had one of those 800 CFM's unless it was something that wasn't published back then due to all the insurance and C.A.R.B .mandates. And as far as looking for another 7040200 EE carbs , then the next time I have to take it to another mechanic , what else is going to go missing? You see my dilemma? But I know already that I can trust you and the work you do because you are knowledgeable and you demonstrate your work . Thank you.
@@arnoldschmidt2753 Chevy never used the 800 CFM Carburetor. Pontiac had them on the Ram Air package. Olds/Buick/Cadillac used them I think around 73.
Harold
@@backnine Thank you Again for responding . So that info confirms what I've been reading. Now you spoke about the bowl vent and hot engine compensator bi metal valve on the back of the main body . My7040200 EE had those . but I just can't just buy those 2 parts unless I have the correct body . The bowl vent is available but doesn't it work in tandem with the bi metal hot Idle compensater design ? Thanks again Sir.
When it gets hot (20+ mile drive) the carb acts like is starves for fuel and cannot run faster than an idle.
Let it idle a little while and you can accelerate a second or two and then starve again.
Any idea?
If is getting good fuel supply and running with no fuel filter ( has a separate inline fuel filter outside of the carb).
Could it be the float gets hot and floats too high (it ran fine for many years but has recently started doing this)
Sounds like a fuel supply problem. Fuel pump not putting out after it gets hot/Needle seat sticking. If the float was to high the engine would be flooding out.
@@backnine Is it possible for the float to sink when it gets warm?
I will look at replacing the float, needle and seat.
It has a new fuel pump that gets plenty of fuel to the carb inlet (tested by cranking engine with inlet tube disconnected and stuck into container to catch gas).
THANKS!!!
How do I contact you for restoration info? Great 3 part series, watched the plating vid, nice setup.
chucknorbid@gmail.com
What do you charge to do a rebuild of this detail?
220.00
@@backnine Even though my qjet is for my old motorhome I'd love my carb rebuilt to this level of care and detail... I've e-mailed you (first name Anthony). You're a true craftsman and your work here is beautiful
does the needle wire go on hump side of the back of the float bar or the flat side ??
Hump side, but not on the hump itself.
Regardless of where it goes on the flat parts on either side of the hump, it still operates the same. Its no so much the spring that's going to make a difference in filling/refilling correctly, that's the float's job. The float lifts up, and it lets the needle valve drop and start closing the fuel off, the float eventually rises and physically pushes down on the needle to shut off fuel completely.
Regardless of where the spring is, as long as the float is lifting it out and the float can go all the way up to where it pushes the needle down, then it's fine (that's why there's a measurement spec for where the float height should. If it's too low, the float will top out against the air horn and the needle wouldn't close all the way. If it's too low, it'll shutoff the needle/valve prematurely and then engine will starve for fuel/lose power overall when trying to really getting into the throttle because the valve is closing too much too early.)
Is it possible to get some help/ideas with problem i am having the my quardjet?
chucknorbid@gmail.com
Where can i buy a float tool. I have adjusted the float 4 times, and still not getting it to run correctly.
Why do you think the float level is problem? Is fuel over flowing?
The first adjustment the carb was flooding, gas coming out the top, the next 4 adjustments on the float was not getting any gas. It would start with Starting fluid.
Hi Reed
You probably have a bad needle seat assembly or you have crap logged in the seat area. Also the D clip (Float Pivot) that holds the float in has to be slightly above the body so the air horn pushes it in its seat. The tool I show on the video is just a depth gauge you can find on eBay. Also if you have a brass float it might be leaking and filling with fuel.Use the black solid float
Harold.
Harold, Well this is where i feel really stupid, reset the float adjustment and was checking if the primary's were plugged nope, checked the accelerator pump and i was missing the spring underneath, Duhh. Thanks for your help
what did you soak it in to get it so clean
I use Berrymans Chem dip to clean the grease and carbon off then I glass bead them with 140 mesh before plating.
The main reason for failure is putting the carb back together.. Thats my opinion..
My God that's a shiny quadrajet.
Hola
Quit that smoking