How to Convert an M4MED to a Manual Choke

The M4MED is one of the Quadrajet models of carburetors developed by the Rochester Products Division of General Motors. It is characterized by a centrally located float that is highly resistant to level changes because of the sudden cornering or acceleration common in off-road driving, a dual capacity pump solenoid and an automatic choke. The Quadrajet carburetors have not been included with General Motors automobiles in several decades, and as such, if you are experiencing problems with your engine choke, you may want to convert it to a manual system.

Instructions

1

Disconnect the intake valve rod connecting the choke thermostat and the carburetor and bend it at a 90-degree angle near its base with your pliers.

2

Set the dash bracket underneath the dashboard in a place where it can easily be reached. Mount one of the holes securely in place using the included sheet metal screws.

3

Run the coiled end of the choke cable through the free hole you drilled in your dashboard and secure it tightly around the dash bracket.

4

Drill a hole in the top of the choke shaft straight down approximately 1/2-inch. Use a 7/84 drill bit.

5

Drill a second hole on the side of the carburetor directly across from the throttle linkage.

6

Mount the included s-bracket in the hole your drilled in the choke shaft, using the included self-tapping screws and star washers.

7

Install the included l-bracket to the hole you drilled in the side of your carburetor using the included mounting nuts. Attach the core end of the choke cable to the cable clamp and tighten its screw to hold the cable in place and complete your conversion.

8

Turn on your engine and pull on the choke several times to ensure that it is working properly.