It slightly restricts it + I heard all it did was restrict a 17.5 carb to the 12mm carb by using brass plate + tha arm in the air box
the carb i have is stamped 12 not a 17.5 with a restricting plate fitted do the 12mm carbs come with bigger main jets than the 17.5 or am i better just to replace the carb
No. Just no. It's to get the correct air fuel ratio so they can use as small of a jet as possible to get the best fuel economy. Yes it should be removed when you tune it but not before as it is not a restriction.
My zip ive just got it back on road and ive been clocked doing around 60-65 by few mates in theyre cars i know its not accurate but its theyre abouts 60ish and my zip is 50cc and has 21mm carb, variator, pipe and set up perfect.
mine will do 35mph with a standard 12mm carb and washer removed anyone know the standard jet sizes on a 17.5 carb
Standard is 53 deristricted 56 but I'd just remover brass plate + sleeve from air box and put a 60 main jet with standard exhaust and 63 - 66 main jet for a deristricted sports pipe
just had another go on my friends totally standard aircooled zip it wheelies really easily and does 55mph on the level, my mk1 zip has the exhaust de restricted and the washer removed and the most i can get it to do is 42mph plus theres not a chance it could ever wheelie is the 12mm carb restricting it this much or is there any other restriction i have missed ,