[Purdy Swoft]

I run dual updraft carbs on two of my model A's . Running dual updraft carbs isn't as copmplicated to tune as a dual downdraft setup . People that have never ran dual carbs often get the setups confused . This is usually because of what they have read or heard about running dual down draft carbs . With an open plenium manifold and updraft carbs you can disconnect the linkage and check the carbs one at a time while the car is parked and running . One carb will still feed all of the cylinders . You can rev one carb at a time and see how it runs . I doubt that you have a carburetor problem . If you have one good carb it would still run the car . you probably wouldn't know if the other carb was actually working unless the linkage was disconnected and each carb was tested one at a time as I described above . What I'm getting at is its not likely that both carbs would go out at the same time . I would remove both of the inline filters as they are not needed in any case . I don't know what that red thing is that connects between the glass bowl filter and fuel line but it could be a problem and I would remove it . The less parts that the fuel has to flow through before it reaches the carburetor , the better . Seeing that the glass bowl filter isn't full of gas usually indicates an air block . Gas doesn't easily flow through an air block unless the choke is applied and then it still usually doesn't run very good . Imagine how much gas could be flowing while choking both carbs . I only choke one carb . Choking two carbs is just way too much . If you have ever looked at multi card setups on later cars, they only choke one carb . I had my share of problems with glass bowl filters . I now only use the old original style cast iron bulb filters .The only filters that you need is the firewall mounted filter and a stand up filter in the cut off valve under the tank . I consider the stand up filter a must and use it on all of my model A's . It doesn't take a lot of rust or trash to stop up the cut off valve and starve the engine . The stand up filter stands up in the tank and will filter out any rust or trash inside the tank . I would feel out the fuel lines and fittings for a leak . It doesn't take much of a crack in a fuel line or fittings to cause a problem with gas flow with a dual carb setup , its happened to me !!! It could be a vacume leak anywhere from the carb flange to the manifold connection at the engine block. Carburetor cleaner sprayed around these connections while the engine runs will help detect the vacume leak . The engine will speed up when carb cleaner is sprayed over the leak , be carefull . There is al;so the possibility of vacume leaks , anywhere ftom the vacume line connection at the intake manifold to the vacume wiper motor if you use one . I would first plug the vacume hole in the intake before testing the engine for vacume leaks . this should make it easier to single them out . The only way that you would ever get a vapor lkock would be if you were runningethanol fuel . If you have run or left ethanol fuel in the tank, this could be the whole problem. If ethanol fuel has caused the problem it will need the tank and system to be drained and flushed . the jets in the carbs will also need cleaned and compressed air blown through the jets and passages . Just a few thoughts of possibilities .