My Spanish Webers came with "50" accel jets. That means 50% bypass back to the float bowl. I've not seen them available anywhere, but they seem to work well. I found a reference to accel pump adjustment somewhere, maybe the Weber CB Performance book, maybe on the samba, but can't remember exactly where I read it. Anyway, the reference said that VW engines REALLY like the 50% bypass jets.
EDIT:
Found them, labeled 0.55. So maybe a .55mm hole, or 55% bypass, IDK. See that hole drilled in the side? That hole is what bypasses some fuel back to the bowl.
https://www.mooreparts.com/emp...CEAQYBSABEgIF3_D_BwE
And here, with explanation:
https://www.pegasusautoracing....on.asp?Product=79701
The good news is you can tune the amount of bypass. It works backwards though:
000 is 100% accel shot(zero bypass) to 1.00(minimal bypass). Then fine tune with the threaded rod/pump stroke.
The portable/temporary wideband gauge has turned out to be one of the best tools I've purchased. If only I could get my customers to weld in a fitting on their exhausts.....