• Required reading for all forum users!!!

    Welcome!
    Register to access the full functionality of the GSResources forum. Until you register and activate your account you will not have full forum access, nor will you be able to post or reply to messages.

    A note to new registrants...
    All new forum registrations must be activated via email before you have full access to the forum.

    A Special Note about Email accounts!
    DO NOT SIGN UP USING hotmail, outlook, gmx, sbcglobal, att, bellsouth or email.com. They delete our forum signup emails.

    A note to old forum members...
    I receive numerous requests from people who can no longer log in because their accounts were deleted. As mentioned in the forum FAQ, user accounts are deleted if you haven't logged in for the past 6 months. If you can't log in, then create a new forum account. If you don't get an error message, then check your email account for an activation message. If you get a message stating that the email address is already in use, then your account still exists so follow the instructions in the forum FAQ for resetting your password.

    Have you forgotten your password or have a new email address? Then read the forum FAQ for details on how to reset it.

    Any email requests for "can't log in anymore" problems or "lost my password" problems will be deleted. Read the forum FAQ and follow the instructions there - that's what we have one for...

  • Returning Visitors

    If you are a returning visitor who never received your confirmation email, then odds are your email provider is blockinig emails from our server. The only thing that can be done to get around this is you will have to try creating another forum account using an email address from another domain.

    If you are a returning visitor to the forum and can't log in using your old forum name and password but used to be able to then chances are your account is deleted. Purges of the databases are done regularly. You will have to create a new forum account and you should be all set.

Hoses On Carbs

  • Thread starter Thread starter angus chapman
  • Start date Start date
A

angus chapman

Guest
hi all

just wondering - i have 3 black hoses/tubes connected to the carbs on my 78 gs750e. The centre one (between 2 and 3 carb) is blocked off, while the outside ones are open. is this correct? what do they do? should the outside ones be blocked off like the centre one?

cheers
gus
 
I am going through this with my bike right now. On mine the center tube is fuel from the tank, tee'd into the #2, #3 Carbs. The two outside ones are vent tubes, and just lead towards the ground from what I've read in the old posts.
 
Possibly the 2 outside tubes are overflow-vents like said before, yes, leave open, usally run up and over and behind the air box and then down toward the ground.

Possibly the center tube that it blocked off, is the vacuum line. Is it attatcehd to the intake boot of carb #2? If so, then , yes it is the vaccumn line that is intended to operate the automatic petcock. But maybe you no longer have that.

In your accounting of the lines going to the carbs, you didnt mention one that would be the fuel feed , er, petrol supply.
 
The tubes you are referring to are for ventilation and vacuum. The two outside tubes are vented to atmosphere. If you have pods on the bike, leave the tubes off. The center tube is vacuum to your petcock. If you don't have a vacuum petcock, the center one gets plugged.
 
make sure your route those vent tubes correctly or you will have loss of power at high speeds, trust me. Mine route down the inside of the side covers.
 
i do have k&n style pods on the bike - was is the reason for taking the tubes off then? a friend of mine told me that the tubes were for adjusting the carbs and they should be blocked. i put screws in the end and i don't know if its psychological or not but the bike seems to be smoother.

i forgot to mention that the bike is fitted with a kawasaki tank, so no vacuum petcock.

cheers
gus
 
i do have k&n style pods on the bike - what is the reason for taking the tubes off then? a friend of mine told me that the tubes were for adjusting the carbs and they should be blocked. i put screws in the end and i don't know if its psychological or not but the bike seems to be smoother.

i forgot to mention that the bike is fitted with a kawasaki tank, so no vacuum petcock.

cheers
gus

According to the carb gurus here, if you have TRUE K&N filters on the bike, it will starve for fuel at high rpms unless you take the vent tubes off. Dyno Jet also tells you to remove the vent lines when you re-jet with their stuff. You may not have a problem if they are not K&N's, but you do need to unblock them. As stated, plug the center nipple if you don't have a stock petcock.
 
Back
Top