So I'm curious as to all the different stock puch intake variances, obviously there is tall and short, round and square, 12 and 14mm.....but then there are restricted ones. . both 14 and 12, which respectively are 8 and 10mm.
How exactly are they restricted, is it just a plastic plug or is there something else used to restrict them? How can they be identified?
I know it's probably a simple question to the old timers, but these bikes are older than me and I never seem to run across them in stock configuration, just piles of parts and such.