hello Thomas,
I have read these posts a couple of times to see if there is anything I can think of.
you are using a different needle and seat on each of these carbs?. sounds to me like it might be simply flooding for some reason. this is usually one of two things -- needle and seat not shutting excess fuel flow off when the bowl is at the right level,and -- the fuel level too high in the bowl,due to an incorrect float level,or a bad float.what floats are in these ?hollow brass or solid float material?
also the screw you speak of at the carb base -- is that the idle mixture screw you are referring to?
do you have a pic or 2 you can post of the set up? springs and all?
regards,Rod
