I have a 1952 Olds., 303 Engine with Rochester 4 barrel carburetor. With the current adjustment, there's a "loping" sound when the car is running. What is the "proper" adjustment for this carburetor?

 

hook up a vacuum gauge to manifold vacuum and adjust for the highest attained vacuum on the gauge. Both A/F mixture screws should be adjusted so that they are about equal turns out from their respective bottomed out positions.

 

Probably a good rule of thumb is turn them until they stop while being careful to not over tighten them. Back them out about 2 turn and them follow the procedure Eric detailed above. It may be possible there could be something else causing your problem. A vacuum gauge is a great tuning tool on these old cars. You may want to tweak your timing using the vacuum gauge too. You should be running at least 15 inches of vacuum if you engine is in fairly decent shape.

 

Thanks' guys!!! I'll give it a try!


Jerry