Carb Mystery Pipe

[Kettle One]

Does anyone know what this pipe does? It's on the right side carb only.

[snydes]

Does the carb have a model version on it? Also check sites like partzilla for an exploded diagram and see if you can find out what it is. My 1WG carbs don't have this

[Kettle One]

It doesn't show up on any parts diagrams. I do see 3FH stamped on the side.

[snydes]

Wait I may have those kind of things on my 1WG carbs. In between carbs in the fuel rails there are 2 pipes sticking upwards that if the carbs are flipped upside down fuel comes outside. Now my guess where mine go are to the what was air box. I have pods so previous owner just snipped the hoses and pointed them upwards and left them open. They could just be a vent that should lead to an airbox

Mine is different but may do same purpose

[Kettle One]

I also have those two vent pipes between each pair of carbs. The mystery pipe is only on Carb #4 (right hand side). I did find out that the 3FH designation was for the 1988 US model with EXUP. I did have a 1WG model before and I don't recall seeing this mystery pipe on them.

[snydes]

Only on a single sounds very odd I have no clue at all. Hopefully someone else has a clue on here

[buzzawak]

Interesting, so the other carbies have the casting for the tube.
From what i can make out the casting is blind (no hole into the body of the carb), so on the FZR's it is actually not used.
Educated guess, on other bikes it would be part of a evaporative emission control system.

Carbies

[Kettle One]

Yes what you have circled on Carb #2 is a blind plug and that is the same on 1 and 3. On #4 (the circle on the left of your pic) is the mystery tube. I attached a length of pvc tube to it and blew through and it does actually blow right through into the carb body right where the butterfly sits. I would think it would have to be hooked up to something otherwise it will let too much air into Carb #4. No clues from any parts diagrams I have looked at. Ideas?

[Kettle One]

Snydes I owe you an apology....the answer is on a Partzilla parts diagram....I was just not looking at the right one!
Turns out the 3FH are California "C" Model carbs. The "C" model bikes have a canister for emissions and there is a pipe that goes from the canister to the carb (#84 in this parts pic).