My IIa not running the best (preignition)
When I tested the fuel by disconnecting the line at the carby I got 2/5 of a wine bottle worth of fuel in thirty seconds.
I also got lots of bubbles
I tried this from all three fuel tanks
The same result from all fuel tanks

Question:

Is this enough fuel?

Are the bubbles normal?

Thanks

Series IIa 2.25L.. manual fuel pump