vm 28 123 OR 4 ?

[Guest]

HELLO Just a quick carb (vm28) question....how can I tell the difference between the carb bodies..if the vacuum pipe comes of between 3 and 4 and the other t pieces are breathers. is there a difference between them? my problem is I have a box of lots of carbs in bits (job lot) I would like to make up a spare set.so I just wondered if there are any id marks, relative to position, or if all the bodies are the same ? I hope that's clear.... ok so I just found out,that one of the carbs is ported to create vacuum but still no idea how to tell them apart ..thanks in advance Simon

[Big T]

Simon,

It's simple

Look in the throat (intake side) and see if it has a port that creates the vacuum. Yes? #3

Now check the hole where the fuel rail goes. Can you see thru it? #2
Can't see thru it? Blocked on the left? #1
Blocked on the right? #4

Each carb is different, so get them in the correct order

[Agemax]

Look at the air mixture screws on the side of the carbs, 1 + 2 face left and 3 + 4 face right (as you sit on the bike)
1 carb has no vacuum port so thats 1 + 2 easily identifiable, and, as said by BIG T, look at the fuel supply ports, No.4 carb will be blocked at the r/h side, No.3 will go straight through. 3 + 4 sorted.

[Sandy]

Once you've figured out which is 1 and 4 you can figure out which is 2 or 3 simply by the orientation of the air adjustment screws.
Edit: Agemax beat me to it.

[SIMONK]

THANKS TO ONE AND ALL . HAVE THEM SORTED, JUST A BIT DAUNTING WHEN THERE IS A LOAD OF THEM..