Thanks for the video. I found it really hard to see down the main jet hole (especially on a Mini) so I instead used a dipstick approach using your idea. I extended & locked the caliper depth gauge to 45mm, dipped it in the hole down in to the fuel until the caliper body seated on the opening and then unlocked and carefully closed the caliper until it got to the wet line - should be around 20mm. Subtract this reading from 45mm gives the depth to the top of the fuel.
The best fuel height I have found is 29mm - 25mm has the fuel too high - See: www.classiczcars.com/topic/44512-setting-weber-dcoe-fuel-level-with-caliper/ and centerlinealfa.com/sites/centerlinealfa.com/assets/files/default/dcoe_setup.pdf I have tried both 25mm and 29mm - 25mm caused a lot of stuttering and hesitation, while 29mm cured everything.
Take the E-tubes out and let it idle for 30 seconds for the carbs to find their level, turn off and as quick as poss check the level as above....... repeat for the other four. You may need to syphon some fuel back out when you have finished because refitting the E-tubes will displace fuel and it will overflow down the venturi's into the inlet giving you the impression it's running mega rich.
