> Last Sunday I thought I would clean up the SU filters as they looked
> dirty. After removing the filters I noticed what felt like wet gas
> right at the intake of the front SU. When I lifting the piston on
> that carburetor I noticed a slight dribble of gas come out of the
> disconnected (now reconnected) vacuum advance tube to the
> distributor. When I put the piston down it stopped & when I lifted
> it again the flow restarted. The next day when I rechecked there was
> no dampness nor dribble out the disconnected vacuum tube.
> Does this sound like float on the front SU is set too high??? I have
> not seen any flow out of the overflow tube.
Could be set too high ... could also just have a piece of crud caught in the
float valve, so it doesn't close entirely. IMO the latter explanation is
> Given that I have not rebuilt SUs in about 20 years, I cannot
> remember if I can adjust that float with the carburetor mounted on
> the engine (just take the top off of the fuel bowel), or if I need to
> completely remove the entire carburetor to do the job?
The float height can be checked & adjusted with the carb still on the car.
Just remove the float bowl cover.
> Any advice would be appreciated.
While you're at it, fish out the float. Shake it to check for fuel inside.
Also check the bottom of the float bowl for crud. Inspect the float bowl
mounting rubbers, they're a common failure point too.