Nice videos on the Quadrajet. All my life since I was about 14, 32 years ago, I've always heard them called Quadrajunk. Never understood why. I think they are great carburetors. Every vehicle I've owned and even my boats that ran Quadrajets ran great. Keep the videos coming. I learn something new every time I watch one.
Great videos! Lots of good tips and advice that will keep you from messing up things. These are great carbs and I’m having fun learning how to tune them Thank you worthy of thumbs up and subscribing
Thank you for posting this video! Although there were differences in my 70 Pontiac 7040264 carb, I was able to change the jets! It was a great training aid!
It is also a good idea to mention that the tiny clip on the needle does NOT go through one of the holes in the float arm. There is a recommended sequence the bolts should be tightened. It's not too critical though.The roll pin is 3/32". Thanks for the video.
Nice Videos, if the holes in the black plastic piece where the metering rods go through were smaller it would help getting them centered, I just mashed one of mine. Thanks
there are quite a few q-jets without APT. generally speaking if your casting doesn't have it there isn't anything to be done about it. look just in front of the vent hole, if you see a brass or aluminum plug you can pull that, tap and install APT. it's a bit difficult and needs to be PRECISE, but it can be done.
ESTE ARTICULO COMPLETA TOTALMENTE EL TRABAJO DE DESARME Y ARMADO DEL CARBURADOR.... MUY BUENO..... LASTIMA QUE NO ESTA TRADUCIDO AL ESPAÑOL PORQUE NO ENTIENDO BIEN EL INGLES---GRACIAS
Very nice informative video. Nice job! Do you have a permanent fix for the Primary and Secondary aluminum plugs. Others who have uses epoxied Allen screws report in a year they fail and leak again.
changing jets changes the size of the orifice gas goes thru to get to the carb. changing metering rod sizes will change the amount of fuel the carbs gets as well. if you are new to q-jets there is a great book avail. google it, the author is Cliff Ruggles - it has more info than you can imagine; very informative.
There is a specific tightening sequence for the top screws on a quadrajet. It's in the book, I won't tell you so that you will have a reason to read it. LOL The book by Doug Roe is good reading. You can download the GM book from "old car manual project."
Thank you. This was very helpful and extremely well done. I have a GTO coming and I live at 5300 feet, so I will need to re-jet for the altitude. Hopefully I don’t have to touch the metering rods, just the jets, but I’ve never worked on a Quadrajet before. Any advice for what jets and or rods to use for this altitude?
Great video Ed! Getting ready to re-jet my Q-jet on a mildly built 454 that was originally a BBC carb (7041205), but was rebuilt for small block duty. Now its time to take it back to original specs and see if thats good enough or if I'll have to re-jet one more time to feed the BBC. Any truth to the advice to only go up 10% at a time on jet size? Thanks again!
On my carb 7044213 is doesn't have the hole in the top where you are adjusting the metering rod piston. Can I drill a hole in mine and just use a pipe plug afterwards or would it be ok to just leave it open? I don't want to keep having to remove the top and make adjustments. My carb is running rich at at idle and I was told I need to go from 68 jets to 75 and from 36 prim rods to 43B. Would that help with the rich idle? Seems like going to larger jets would just make it worse. Thanks
it's at #69 and has been for a while - i'll be going back to #68, but right now i'm involved in another project (83 Cutlass Cruiser-vids here on that as well) that's taking my time up
Great vid thank you ,,Question I have a 79 Trans am with the 403 with the rochester ,,What size jets would it have ? or would in be stamped on the jet ? And where can I buy the jets ?
Awesome tutorial Mr. Beach, my question which you may have answered another time, is what is the best way to figure out which gasket goes between the air horn and the body if you don't have the previous gasket. Mine is a Carter 7043202, fs, c3. Thanks for any help.
Hi, I enjoyed your video.Question, After the APT screw contacts the pin on the power piston, you then turn the adjustment screw 3 turns?I wasn't quite sure, you mentioned 9 turns untill the piston is forced out of the bore?Your video is the first one I've seen that even mentions that adjustment. Thanks, Hoyt
I have a corvette with a 350 my problem is lean my plugs always look brand new no splatter just brand new looking carb is a q jet that runs very good no bog or poping back runs awesome but worried im too lean burn valfs up or do damage to it
Man thanks a ton for your video , I just got a rebuilt 700 quad and installed it lol I lost more that half the power I had with my tuned in holly so I have some big time tuning to do to the Qj . I have never had one and was intimated till I watched your video. I have a pontiac 400 with ram air 3 heads and a ram air 4 cam since it's stock stuff I was thinking I may be able to dig up GM's spec's for the Qj when this combo came from the factory ? any ideas on that ? thanks again :) Marc
I know this is a bit dated but, if you still receive comments, how many jet sizes can you go with the same metering rods? and can you get a strip kit similar to the edelbrock strip kit for the quadrajet? Thanks
So I also changed my keys to the smaller #67 and my metering rods don’t seat all the way down so they make longer ones? My car burns a lot of gas and runs rich
Also a question when you talk about 67 and 69 jets what do they make the carb do? More power or save more gas or what?..sorry I'm REALLY new at carbs..
Hi Ed, i got a R4-4MV Quadrajet (Nr.:7042902) and the secondary will not open. i checked the manual but there is no pic close enough from the throttle linkage between the primary and the secondary to see what´s wrong with my carb. Can you hlep me out? Thanks for your effort. :-) Greet from Bavaria
If you never figured this out, check on the opposite side of the carb from the throttle linkage, look for the secondaries throttle shaft and see if the lockout/block/tab is moved away from the pin going through the shaft. If it's contacting the pin it stops the secondaries from opening because the choke has not turned off or isn't wired correctly. I just tied the block back away from the pin since my choke is broken, but you aren't supposed to stomp it until it's warm if you do this. That block keeps you from opening the secondaries on a cold motor.
So if I am running lean will I need to adjust the metering rods with that screw to richen it up. It is firing back thru the carb when I give it a good stomp on the gas.
EdontheBeach Thank You Ed. We had to adjust the timing high cause of a bad harmonic balance. Then we put a new Harmonic balance in it, set the timing, set the float, and idlers adjusted, Number one cylinder at top dead. Just had a new carb kit installed. Would a check ball be stuck also?
Nice videos on the Quadrajet. All my life since I was about 14, 32 years ago, I've always heard them called Quadrajunk. Never understood why. I think they are great carburetors. Every vehicle I've owned and even my boats that ran Quadrajets ran great. Keep the videos coming. I learn something new every time I watch one.
Great videos! Lots of good tips and advice that will keep you from messing up things. These are great carbs and I’m having fun learning how to tune them Thank you worthy of thumbs up and subscribing
Thanks buddy
I thought I knew a lot about quadrajets. Turns out not to be the case. Learned a lot today great video.👍🇺🇸🇺🇸
Thank you for the video sir! It was extremely helpful
information epically valuable! I haven’t seen anything this quality level and changing jets great valuable stuff
Thank you for posting this video! Although there were differences in my 70 Pontiac 7040264 carb, I was able to change the jets! It was a great training aid!
Awesome 2 videos, I learned a lot about the qjet here...
Very nicely explained. Great information. Thank you so much ...
It is also a good idea to mention that the tiny clip on the needle does NOT go through one of the holes in the float arm. There is a recommended sequence the bolts should be tightened. It's not too critical though.The roll pin is 3/32". Thanks for the video.
great information. never seen one go back together to easily
great vidieo i am going to dig out my old q jet and you remind me of my shop teacher god bless
Nice video series of the Q-Jet. Suggestion, it would be great to see a before and after video showing the difference of how the engine runs. Thanks.
Thanks ill be sure to get that service manual. Great videos
Nice Videos, if the holes in the black plastic piece where the metering rods go through were smaller it would help getting them centered, I just mashed one of mine. Thanks
there are quite a few q-jets without APT. generally speaking if your casting doesn't have it there isn't anything to be done about it. look just in front of the vent hole, if you see a brass or aluminum plug you can pull that, tap and install APT. it's a bit difficult and needs to be PRECISE, but it can be done.
ESTE ARTICULO COMPLETA TOTALMENTE EL TRABAJO DE DESARME Y ARMADO DEL CARBURADOR.... MUY BUENO..... LASTIMA QUE NO ESTA TRADUCIDO AL ESPAÑOL PORQUE NO ENTIENDO BIEN EL INGLES---GRACIAS
Very nice informative video. Nice job! Do you have a permanent fix for the Primary and Secondary aluminum plugs. Others who have uses epoxied Allen screws report in a year they fail and leak again.
changing jets changes the size of the orifice gas goes thru to get to the carb. changing metering rod sizes will change the amount of fuel the carbs gets as well. if you are new to q-jets there is a great book avail. google it, the author is Cliff Ruggles - it has more info than you can imagine; very informative.
There is a specific tightening sequence for the top screws on a quadrajet. It's in the book, I won't tell you so that you will have a reason to read it. LOL The book by Doug Roe is good reading. You can download the GM book from "old car manual project."
yes, I use 3 turns as a starting point, some people use 2, others use 5 or 6 - it's just a starting point used as a reference for the final fine tune
Thank you. This was very helpful and extremely well done. I have a GTO coming and I live at 5300 feet, so I will need to re-jet for the altitude. Hopefully I don’t have to touch the metering rods, just the jets, but I’ve never worked on a Quadrajet before. Any advice for what jets and or rods to use for this altitude?
Great video Ed! Getting ready to re-jet my Q-jet on a mildly built 454 that was originally a BBC carb (7041205), but was rebuilt for small block duty. Now its time to take it back to original specs and see if thats good enough or if I'll have to re-jet one more time to feed the BBC. Any truth to the advice to only go up 10% at a time on jet size? Thanks again!
On my carb 7044213 is doesn't have the hole in the top where you are adjusting the metering rod piston. Can I drill a hole in mine and just use a pipe plug afterwards or would it be ok to just leave it open? I don't want to keep having to remove the top and make adjustments. My carb is running rich at at idle and I was told I need to go from 68 jets to 75 and from 36 prim rods to 43B. Would that help with the rich idle? Seems like going to larger jets would just make it worse. Thanks
it's at #69 and has been for a while - i'll be going back to #68, but right now i'm involved in another project (83 Cutlass Cruiser-vids here on that as well) that's taking my time up
Good Video Ed! Are the #67 Jets doing the job you want?
Great vid thank you ,,Question I have a 79 Trans am with the 403 with the rochester ,,What size jets would it have ? or would in be stamped on the jet ? And where can I buy the jets ?
Awesome tutorial Mr. Beach, my question which you may have answered another time, is what is the best way to figure out which gasket goes between the air horn and the body if you don't have the previous gasket. Mine is a Carter 7043202, fs, c3. Thanks for any help.
it will be evident when you get your rebuild kit, as a rule of thumb the thinner of the two is below and the thicker above
Hi, I enjoyed your video.Question, After the APT screw contacts the pin on the power
piston, you then turn the adjustment screw 3 turns?I wasn't quite sure, you mentioned
9 turns untill the piston is forced out of the bore?Your video is the first one I've seen that even mentions that adjustment. Thanks, Hoyt
I have a corvette with a 350 my problem is lean my plugs always look brand new no splatter just brand new looking carb is a q jet that runs very good no bog or poping back runs awesome but worried im too lean burn valfs up or do damage to it
Man thanks a ton for your video , I just got a rebuilt 700 quad and installed it lol I lost more that half the power I had with my tuned in holly so I have some big time tuning to do to the Qj . I have never had one and was intimated till I watched your video. I have a pontiac 400 with ram air 3 heads and a ram air 4 cam since it's stock stuff I was thinking I may be able to dig up GM's spec's for the Qj when this combo came from the factory ? any ideas on that ? thanks again :) Marc
I know this is a bit dated but, if you still receive comments, how many jet sizes can you go with the same metering rods? and can you get a strip kit similar to the edelbrock strip kit for the quadrajet? Thanks
So I also changed my keys to the smaller #67 and my metering rods don’t seat all the way down so they make longer ones? My car burns a lot of gas and runs rich
I meant jets…
If that carb is a 705, what was the factory setting on the APT ? Thank you for your time. I bought one in pieces and am currently looking to rebuild.
Also a question when you talk about 67 and 69 jets what do they make the carb do? More power or save more gas or what?..sorry I'm REALLY new at carbs..
why the 3 turns in the mid rods ???
great ,great ,video .... cheers .....
Any thoughts on a jet size for my 305 basically stock? How would I go about cleaning the jets if there is a little bit of build up?
Hi Ed, i got a R4-4MV Quadrajet (Nr.:7042902) and the secondary will not open. i checked the manual but there is no pic close enough from the throttle linkage between the primary and the secondary to see what´s wrong with my carb. Can you hlep me out? Thanks for your effort. :-) Greet from Bavaria
If you never figured this out, check on the opposite side of the carb from the throttle linkage, look for the secondaries throttle shaft and see if the lockout/block/tab is moved away from the pin going through the shaft. If it's contacting the pin it stops the secondaries from opening because the choke has not turned off or isn't wired correctly. I just tied the block back away from the pin since my choke is broken, but you aren't supposed to stomp it until it's warm if you do this. That block keeps you from opening the secondaries on a cold motor.
So if I am running lean will I need to adjust the metering rods with that screw to richen it up. It is firing back thru the carb when I give it a good stomp on the gas.
if it's backfiring through the carb you have other problems - anywhere from used up accelerator pump to bad timing, bad valves, etc.
EdontheBeach Thank You Ed. We had to adjust the timing high cause of a bad harmonic balance. Then we put a new Harmonic balance in it, set the timing, set the float, and idlers adjusted, Number one cylinder at top dead. Just had a new carb kit installed. Would a check ball be stuck also?