ROCHESTER QUADRAJET CARBURETOR 4MV REPLACEMENT “mechanical / divorced choke” also known as “remote choke” 4 Barrel Quadrajet with “SIDE FUEL INLET”. Compatible with all Chevy/GMC trucks and cars 1966 thru 1973 Available for 327, 350, 396, 400, 402 or 454 Engines Bolts on to any Quadrajet/Spread bore GM style intake manifold
May 30, 2019 · Remove the 3 screws that hold the choke element, remove the choke (the electric choke is the one with the spring-like flat metal wire inside and the 12V on it). Check if the choke cam is misplace (green arrow), the good position is shown on the picture. The 2 cam should meet at the 2 red arrows when the carb is at the close position and cold.
A group for both the average fans and the hardcore Rochester Quadrajet carburetor fanatics.
I am in agreement the the Quadrajet carb is a great bit of engineering, as they went on so many different engines with different displacements. My engine has a mild cam and 15 in. of vacuum is about the best that I can do, but it runs very well. I always adjust with a vacuum gauge, but I did adjust for high RPM years ago. Whatever works. Reply ...
1. Set the idle speed, then find the stupid mixture screws. With the engine warm. 2. Gently turn both screws all the way in counting turns. 3. Return them to where they started assuring they are both exactly the same number of turns out. 4. Fire the engine back up.
Today, if seemed to require choke to keep it running even after warming it up. It sounds like a tractor at the fair at idle. Off idle, it seems to run ok, and it seems to have normal power. I've tried to adjust idle mixture with no change. Pouring a bit of liquid fuel system cleaner down the throat of the carb makes it run normal.
1980 Chevrolet truck Quadrajet, M4MC type (hot air choke), no. 17080213. M4MC Quadrajets have an integral choke and a different airhorn design; also, the throttle shafts are longer than in 4MV carbs. Starting in 1968 carb numbers were stamped on the driver's side, near the back.