Carter B&B Problems & Solutions
Carter B&B, BBR Carburetor Problems & Solutions
Below you will find questions that users have asked about the Rochester 1 barrel carburetor. The questions are followed by our best guess answer. We say best guess, because we don't have the carburetor in front of us and users often leave out important information.
Engine Only Runs When Choked
I bought a rebuild kit from you almost a month ago. after rebuilding my Carburetor i can only get the engine to run with the carburetor on full choke. I have tried adjusting the idle set screw, but it does not make a noticeable difference. I watched your video on BBR carbs and followed the instructions carefully. What can i check or do to make it work again?
This is an indication of one of two things.
1 - There is too much air, possibly caused by a vacuum leak.
Using a spray carburetor cleaner (be sure you get the straw that connect to the spray nozzle), spray around the throttle body, both where it mounts and where the throttle body connects to the float bowl. If the RPM changes, then you found a vacuum leak.
Check other possible connections for a vacuum leak. The intake manifold is one of these.
If the problem is new since you did the rebuild, then you could probably concentrate on the carburetor.
Most of the kits have multiple throttle body gaskets and it would be easy to install the wrong gasket. This is a common mistake I have made more than once. Carefully inspect to make sure air isn't being allowed to enter the carburetor at that point.
2 - There isn't enough fuel.
Recheck the float level.
Make sure the needle isn't sticking closed. Cleaning the viton tip with mineral spirits can help with this.
Poor fuel pump pressure could also be the cause. Test the pressure and compare with what is printed in your engine manual. I don't know what is should be and would have to refer to a manual myself.
Look for any restrictions in the fuel line. Where there is rubber line, replace with high quality fuel injection hose. Ethanol will eat the inside of any rubber line.
Did you run thin wire down all passages. Ethanol leaves residue behind that cleaners can't get out.
Gas Leaks Out Throttle Shaft
This situation probably indicates that the carburetor is flooding (too much fuel). Excess gas runs down the carburetor throat, hits the throttle valve and runs out the throttle shaft. This does not necessarily indicate that the throttle shaft needs to be bushed. It does indicate that the carburetor is putting out too much gas. Probably dirty and needs cleaning.
Can I get main jets?
Main jets are no longer being produced that we know of.
Your solution to different jet sizes are to drill the existing hole to a larger size, or if you need to reduce the size solder the hole shut and drill out to a smaller size. Not the perfect solution, but does work.
Excessive Fuel in the Bore
You are probably flooding (getting too much fuel in the bowl).
Test the fuel pump to be sure it isn't putting out too much pressure. Check your motors manual for the specification, but probably around 4 lbs.
Make sure the needle & seat has the gasket installed and that it isn't damaged in some way.
Make sure the old needle & seat gasket is removed. Any problem with the gasket would allow fuel to flow around the seat.
Test the brass float - heat up water and immerse the float. Any bubbles indicates a leak.
Make sure the float isn't sticking when moving it up and down. A worn float pin would do this.
The needle may have been damaged when installing. They are easily damaged. With the float up and the needle closed see if you can blow through the needle & seat. Look at the needle to see if there are any marks on the needle.