Stan Galat posted:Now we’re getting somewhere.
If they are Kadrons, they’re probably leaking by the needle and seat internally, and flooding over the top of the bowl and down the throats.
Will it idle for a minute straight, without blipping the throttle? Or do you need to “clear it out”?
I encourage following Stan first on this one.
In my "broad" observations involving a total of 1 speedster (a VS with with 1915, dual carbs), a carb was replaced on two separate occasions over a couple of years. Once when only a few months old, and another time a couple of years later.
Reason: Float bowl problems. The needle valve wasn't closing fuel delivery to the float bowl and raw gas was overflowing directly down the intake manifold. Mileage would naturally be affected as if pouring gas down the drain.
Early symptom: Idle problems, because one side of the engine was in a constant state of "flooding".
Worse, (in the case of my observations) when parked long enough, gas continues to trickle from the tank thru the carb and overflow down the the intake, ultimately filling the intake as well as filling the carb all the way to the top. If an intake valve were open, then the cylinder would fill up before gas backed up through the intake and overflowed to the top of the carb. (Of course the gas in the cylinder would leak past the piston rings and now gas is in the crankcase contaminating the oil. And, this is compounded by nothing good is about to happen if trying to start the engine with a cylinder full of gas on the compression stroke.)