You must have a bad core then……
The nicer the core, the less trouble to service and less cash outlay…..if Lars has to pull a lot of parts from stash or fix boogered thing done by someone else’s hand…..the price goes up pretty dramatically.
You may want to search for a nice core….they are out there…..I have bought six in the last year.

Jebby

 

I'm not gonna spend $500 rebuilding a Q-jet when I can buy a new carb for $400.
I found a used but rebuilt Holley 4165 Carburetor for $400 so I may go that route.
A huge red flag is when he called my carb "junk" before ever even looking at it.

 

Lars can be "blunt". But his many years of experience proves that he is seldom (if ever) wrong about a previously 'rebuilt' Q-Jet. Recent (last decade or two) rebuild shops just disassemble, clean, and RANDOMLY re-assemble parts to create carbs. It is VERY unlikely that something being rebuilt by anyone other than Cliff or Lars is being rebuilt WELL.....
Good luck with your carb replacement search....

 

I know this much:
I do about three Q-Jets a year….no way would I touch one for $125.
If it had a bog….then you sent it off and it still has a bog, then the guy that did it doesn’t have a handle on how the Q-Jet works. You are not getting fuel when the secondaries open plain and simple.
A used 4165 is another gamble.
I think $500 is a bargain for a carb that is guaranteed to work when installed.
You could still hunt for a good core.

But first things first…..pull the secondary rods out and see what is going on. Is the cam functioning? What is the number on the rods?
The secondary system is a very simple system….but you are not getting fuel for whatever reason.

Good luck to what you decide.

Jebby

 

Who is Cliff? Do you have any contact info?

 

The carb came on my 1975 Corvette....I didn't buy this carb from him for $125 like it appears some people are thinking., it appears all he did to it was clean it so I highly doubt there are any "modifications" done to it internally. he did tell me one of the external vacuum diaphragms was bad and it was replaced with a new one and the heat choke replaced with an electric choke. How much should I expect to pay to have the carb rebuild and working well by a reputable rebuilder? is it $300? $500? $900?

 

Well I start at $200…with your nice core…..so ????
If it needs parts….repair of any kind….that number can double easily…..this is why a nice core is a value…..
But let me say this….for $125, is does the same thing it did before you gave it to him…..which means he cannot identify issues as seen with the carb apart….how much would you pay an expert to make it work the way it should? Value is where you put it…..which is generally pay now or pay later….

Jebby

 

This is also an option:
A-Team Performance 1903 Rochester Quadrajet Carburetor 75-85 Hot Air Choke - Walmart.com

A reman Q-jet for $299 ...looks identical to mine.

 

Personally, I would not bolt that onto an engine for free.......you have to understand how bad the Commercial Q-Jet market is to truly appreciate what is happening there......
Cliff and Lars are not wrong by saying practicing your hook shot for the trash can is the thing to do with them.......
About 2 of 10 Commercial carbs work as intended......and these scheisters get by selling them to the novice who are convinced it is the carb that is the problem and when they bolt this on...they just chase their tail. Oh they will send you another one too in exchange, but how many time do you want to deal with it? These places play on the cost vs. risk business model for which they are always ahead no matter how many of them are bad.
There are legit rebuilders out there.....but most of them will ONLY use your good core. There is a reason for that.

Here's one for you, I am soon sending my perfect 750HP Holley for my 406 to Michigan where Patrick James of Pro Systems will go through it and set it up for my 406......this fee is $450 which includes a full "rebuild" (gaskets, cleaning).......I am not buying the service....I am buying the knowledge......I know 750HP's like the back of my hand....but I know Patrick has the setup for my 406.....my carb is close as I can get it without a dyno and a shitload of time.....nope- Patrick will get my $450.....

Jebby

 

Oh boy...here we go again!

 

 

Sigh.....you guys are friggin killin me....I just need a running Corvette and my bank account is very small these days. Most of you guys talk like you have money coming out of your ears.
Let me try this another way....I have $300 to spend maximum...is there a solution out there for me?.

 

Carbs are easy enough to rebuild stock IF
the original parts are there.
Some care and knowledge when taking off or installing parts, easy on tightening bolts/screws and watching for misfitting, warped, or binding part fitment.

A good book, vid, or just following the instructions in the build kit.

The secondary butterfly is simple.
engine off, full throttle, and push down on the air valve at the top.
It must open easy with no binding.
If it sticks, there is your problem.
Find where it sticks, gently file the interference.
If it doesn't stick, check the spring adjustment, google foo how to do it.

 

that was too simple of a post.
secondary lockout, vacuum module pulls a cam allowing operation.

pay or get your hands dirty

 

Learning Q-Jets is fun and rewarding......everything you need to know is here.

https://cliffshighperformance.com/

Get his book.....best $20 you will spend.

https://cliffshighperformance.com/pr...et-carburetors

Jebby

 

Ok, I will order the book, I should probably have this around anyway if I'm going to own C3 Vettes.

 

Cliff is Cliff Ruggles...the guy that wrote the book you have just been advised to purchase. If you DO want to get into the 'guts' of carb operation and Q-Jet rebuilding, buy the book. If you don't, save your money because your interest is not at a level where you will dedicate yourself to learning all about it.

Here is my suggestion:
Take as many digital photos of your Q-jet required to see it from above, below and on all sides. Take a close-up shot of the passenger side with the choke mechanism and of the driver's side with the throttle mechanism. Send all of them in an e-mail to Lars (V8FastCars@msn.com) along with your request that he look over your carb and give you an assessment of whether it can be 'corrected' or whether it would be best for you to find an old, original-condition Q-Jet which he could rebuild. Offer to pay for this service so that you can have a defined direction to go in your quest to have a stock engine that works WELL.
If that is not a suitable approach for you, then I recommend that you purchase a spread-bore Edelbrock NEW carburetor (600 cfm) for your car. At least it won't be botched-up like nearly ALL rebuilt carburetors. It won't be stock; it won't be as refined as a well-performing Q-Jet; but it will operate decently and won't 'kill' the wallet. The cost for the new Edelbrock is probably about the same as buying a "good" Q-Jet core carb and getting it rebuilt properly by Lars. But, that is your call. Buying the Edelbrock is easier...getting a good Q-Jet on your engine is "better". But, you are the 'guy in a pickle' right now, so you should choose what will work best for you.

 

I figured I come give you all an update on my 1975 Corvette, I bought a remanufactured carb from a web site called guaranteed carburetors.
I paid $285 because I opted to keep my original carb instead of send it in for a core return. Sending in the core would have saved me $60.
I think the part number was X3-610 and I told them I had upgraded the carb to an electric choke and the new carb came with an electric choke on it...no additional charge.
I installed the carb on the car and adjusted the idle air mixture screws slightly and the car is running great now.

 

I see you may have solved your carb issue with the replacement carb.

Stumbling can be an issue with ignition such as spark plug wire arc'ing on header, incorrect or bad base, mechanical or advance timing. Be sure your ignition is in good working order before blaming the carb.

Then, you can also look at fuel delivery. Is your fuel filter or fuel line blocked. This can impact how much power you can access. Idle and mild acceleration may be fine. Mashing the pedal may overwhelm the fuel flow. Also, check fuel pump and fuel pressure going to carb. Mechanical fuel pump should deliver 5-7psi to carb.

Once all this is sorted, then look closely at the carb.