Hello,
I need some help with my carburetor. I have a 1971 Ford Mustang with a inline six 250. I have a Carter RBS single barrel carb on it (Carter RBS 1V Carb w/Electric Choke, P/N 1-283). As of now, I cannot start my 71 Mustang. Here is the story thus far...I went to start my car last week and while it turned over it would idle briefly and then stall. It did this repeatedly. I tried to spray some carburetor cleaner in the carburetor, but this didn't help. As long as I kept my foot on the gas peddle it would continue to run, but as soon as I let go...it stalled.
I thought maybe it was the carburetor having problems so I tried to change the idle mixture screw to no avail. I turned it out so that it would be a richer mixture, but this didn't work. While the engine would sporadically try to turn over, it stopped starting all together even with my foot on the gas peddle. I tried various idle mixture screw positions and tried to find my original setting, but while it would sometimes try to start, it wouldn't any longer when I pressed the gas peddle. I was also starting to get some backfires in the carburetor itself. I continued trying to make adjustments to no avail.
So, I finally decided to replace the carburetor with another Carter RBS single barrel. The following is a picture -
Before installing it I had a question about a hole in the lower gasket, which I assumed was for a vacuum port under the carburetor, but the hole on the gasket didn't match up with any holes under the carburetor. I am not sure if this is causing a vacuum problem, but my old gasket didn't have any holes at all. See picture below of my current re-manufactured carb.
At any rate, I installed the carburetor with the gasket supplied, and it is acted exactly like my old one was after I made adjustments to the idle mixture screw. It seems like it wants to start idling, but it stalls, or backfires depending on the mixture screw setting. I am not sure what is wrong. Before on my old carb before I made any adjustments at all it at least ran when I kept my foot on the peddle when the engine was revving, but no longer. I don't understand what has happened. It is frustrating. I can't even take it to a mechanic without calling a tow truck to take it there because it won't start. I believe it is possibly something with my setting on the carburetor, but I understand it could be other issues with my engine, ect.
I would like to know if anyone has any experience with my type of engine and carburetor to see what they think. Also, I would really like to know what is the recommended idle mixture screw setting for this carburetor. I have been told after gently seating it that I am to turn it out one and half turns. It came with two turns out. And, I have heard someone in a video say to start with three turns out. I tried just about every position, starting at 1.5 turns out and make one quarter adjustments and trying to start the car all the way to having the screw adjusted to 5 turns out. Afterwards I noticed that the fast idle screw was adjusted almost all the way in. So, I turned that back until it wasn't touching and then back in until it was pushing a little bit. I thought maybe it was letting too much gas in previously by being turned in to far. At any rate, now that it is turned back I am going to wait and try adjusting my idle mixture screw again back to what the carburetor re-manufacturer sent it to me with (two turns out).
Before all of this my car has been running great (other than rough starting for the first minute or so on a cold start). Any thoughts?
Thank you.
I need some help with my carburetor. I have a 1971 Ford Mustang with a inline six 250. I have a Carter RBS single barrel carb on it (Carter RBS 1V Carb w/Electric Choke, P/N 1-283). As of now, I cannot start my 71 Mustang. Here is the story thus far...I went to start my car last week and while it turned over it would idle briefly and then stall. It did this repeatedly. I tried to spray some carburetor cleaner in the carburetor, but this didn't help. As long as I kept my foot on the gas peddle it would continue to run, but as soon as I let go...it stalled.
I thought maybe it was the carburetor having problems so I tried to change the idle mixture screw to no avail. I turned it out so that it would be a richer mixture, but this didn't work. While the engine would sporadically try to turn over, it stopped starting all together even with my foot on the gas peddle. I tried various idle mixture screw positions and tried to find my original setting, but while it would sometimes try to start, it wouldn't any longer when I pressed the gas peddle. I was also starting to get some backfires in the carburetor itself. I continued trying to make adjustments to no avail.
So, I finally decided to replace the carburetor with another Carter RBS single barrel. The following is a picture -
Before installing it I had a question about a hole in the lower gasket, which I assumed was for a vacuum port under the carburetor, but the hole on the gasket didn't match up with any holes under the carburetor. I am not sure if this is causing a vacuum problem, but my old gasket didn't have any holes at all. See picture below of my current re-manufactured carb.
At any rate, I installed the carburetor with the gasket supplied, and it is acted exactly like my old one was after I made adjustments to the idle mixture screw. It seems like it wants to start idling, but it stalls, or backfires depending on the mixture screw setting. I am not sure what is wrong. Before on my old carb before I made any adjustments at all it at least ran when I kept my foot on the peddle when the engine was revving, but no longer. I don't understand what has happened. It is frustrating. I can't even take it to a mechanic without calling a tow truck to take it there because it won't start. I believe it is possibly something with my setting on the carburetor, but I understand it could be other issues with my engine, ect.
I would like to know if anyone has any experience with my type of engine and carburetor to see what they think. Also, I would really like to know what is the recommended idle mixture screw setting for this carburetor. I have been told after gently seating it that I am to turn it out one and half turns. It came with two turns out. And, I have heard someone in a video say to start with three turns out. I tried just about every position, starting at 1.5 turns out and make one quarter adjustments and trying to start the car all the way to having the screw adjusted to 5 turns out. Afterwards I noticed that the fast idle screw was adjusted almost all the way in. So, I turned that back until it wasn't touching and then back in until it was pushing a little bit. I thought maybe it was letting too much gas in previously by being turned in to far. At any rate, now that it is turned back I am going to wait and try adjusting my idle mixture screw again back to what the carburetor re-manufacturer sent it to me with (two turns out).
Before all of this my car has been running great (other than rough starting for the first minute or so on a cold start). Any thoughts?
Thank you.