velocity stacks

[Farmer]

20 mm. is just about the min. requirements. But that matter is always the problem in T3 & 4´s

I talked to a German guy in Holland a couple of years back. He had a 1910 back in a 412 Variant, with better cam -carbs etc. He had a lot of trouble getting the consumpsion right. It would always run rich or lean for him. Right up until he went for the CB "update" conversion. Then fuel economy went back to what is was when stock. (Read 30 % better) He did´nt gain any real power by doing it, exept for a more even torque band. For what it is worth, he and others meant that the horizontal discharge tube is working much better under these tight clearances. (Somebody please explain why !)
Worth considering if things really turn to the ugly.