• 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.

Rookie Carb Question

  • Thread starter Thread starter pnwesside31
  • Start date Start date
P

pnwesside31

Guest
I know this question is horrible, but I'm in desparate need of help. I pulled my carbs to clean them and check them, and when I put them on, I think I connected stuff wrong. The only hose I'm positive of is the fuel hose. I'm not sure where the other hoses go to. Like I said, I'm a rookie. This is my first bike.:)

Carb Connections: (What do these connect to?)
1. Between carbs there are two valves connected to each other through some sort of "T" connection that makes one hose. What does this connect to?
2. On the throttle side Carb, there's a valve right next to Carb Adjuster. Where does that connect to?

Gas Tank Connections:
1. The connection off the petcock and right next the main fuel valve: what does this connect to?
2. Off the Fuel Sender, what does that connnect to?

Thanks for any help you all can provide.
 
The fuel tank nipple goes to the air and away from you so you don't blow up your balls if your fuel guage sensor leaks.
The nipple on the #2 or #3 carb goes to the smaller nipple on the petcock.
The T connections in between the carbs are vent lines and should be open or have a hose that goes to open air.
What year and model is your bike?
 
Thanks for the response. My bike is an 86 GS450.

So, here's what I'm hearing:

Nipple connected to the Fuel Sender and Connected Nipples between carbs with "T": Goes to Air
Nipple on #2 Carb (throttle side): Crosses over, and is connected to small Nipple on Petcock

Is this right?
 
Thanks for the reply. I'm also thinking of getting a new petcock as I rebuilt my current one, and found pieces not working properly that weren't in the rebuild kit. How do I know if it's a GS450L, GS450, or another version? I bought it at an auction.
 
pnwesside31 said:
Thanks for the reply. I'm also thinking of getting a new petcock as I rebuilt my current one, and found pieces not working properly that weren't in the rebuild kit. How do I know if it's a GS450L, GS450, or another version? I bought it at an auction.
Click to expand...

You will not regret that decision... :-\\\
 
Where's the best place to buy this petcock, and quickly:) Another dumb question, what does "prime" do on the petcock. I'm used to seeing "On, Off, and Reserve."
 
Older bikes with a manual petcock had ON, OFF, and RESERVE. These newer petcocks are vacuum operated and unless the motor is running the ON and RESERVE don't flow any fuel, engine vacuum is used to automatically open a valve in the petcock. The PRIME is for when the bike has sat for a while and there is no fuel left in the carb float bowls, turn it to PRIME to fill the float bowls and start the bike then return it to either ON or RESERVE.
 
Ahhh the old "4 hoses and only two places to connect them" trick.

Somewhere in Japan there is a little old retired Suzuki design engineer that is laughing his butt off at all the trouble and confusion he's caused to the Americans.

We are his own, personal, Pearl Harbor.
 
Thanks for all the feedback. An suggestions on good sights that sell petcocks?
 
Here's an update to my situation:

I'm on the verge of looking for new carbs now. Eventhough I've done all the connections everyone suggested (Fuel Sender and "T" connection between Carb Nipples to Air/Right Carb nipple to small Petcock Nipple) and even replaced the petcock with a newer one. I also went through the carbs again, and the same problems are still happening.

The only progress is that I've come to the realization that my carbs aren't sending fuel to the engine properly. One of the ways I found this out was when I blew air into the "T" connection it forced pressure through the carbs and more fuel went into the engine. Once I did that, it started purring, but when I stopped, it started sputtering again.

Once again, I'm at a loss, and have no idea where to go. Does this really mean I need new carbs?
 
pnwesside31 said:
Here's an update to my situation:

I'm on the verge of looking for new carbs now. Eventhough I've done all the connections everyone suggested (Fuel Sender and "T" connection between Carb Nipples to Air/Right Carb nipple to small Petcock Nipple) and even replaced the petcock with a newer one. I also went through the carbs again, and the same problems are still happening.

The only progress is that I've come to the realization that my carbs aren't sending fuel to the engine properly. One of the ways I found this out was when I blew air into the "T" connection it forced pressure through the carbs and more fuel went into the engine. Once I did that, it started purring, but when I stopped, it started sputtering again.

Once again, I'm at a loss, and have no idea where to go. Does this really mean I need new carbs?
Click to expand...
When you say "newer" petcock, do you mean NEW or a newer version of the one that was on there? If its the later, GET RID OF THAT PIECE OF CRAP PETCOCK AND BUY A NEW ONE. Those goofy petcocks are a PITA to get primed, and get fuel flowing to the carbs..Blowing on the hoses will help, but you'll likely flood it just as easily as doing the job. Get the replacement job, spend the money, and dont worry bout it for the next 20 years. If your carbs are clean, set up propperly, and have new orings as they should, there is no reason they dont flow correctly. There are no mechanical reasons anyway. Another thing you can try to PROVE the petcock is bad is to hook up a temporary tank, plug the vaccum line from the number two carb with a screwdriver, and see if the bike fires up that way. If it does, you know then that the petcock is at fault. Another possibility is a faulty gas cap vent...
 
You're right, it's a NEWER one, but it works pretty good. All positions on the petcock work correctly. Just to be clear, I keep the carb #2 hose plugged with a screwdriver, and try to start it?

Also, I really feel like I did everything I could to fix up those carbs, but it's clear that the problem is still the carbs. You mentioned that the #2 carb nipple is a vaccum, but it seems like it blows externally, is that correct?

The only thing strange I noticed about the carbs is that on one of the bowls, the the release valve screw is puttied in, and I wouldn't be able to release any fuel if I had to, but when it was running, it didn't bother anything.
 
pnwesside31 said:
You're right, it's a NEWER one, but it works pretty good. All positions on the petcock work correctly. Just to be clear, I keep the carb #2 hose plugged with a screwdriver, and try to start it?

Also, I really feel like I did everything I could to fix up those carbs, but it's clear that the problem is still the carbs. You mentioned that the #2 carb nipple is a vaccum, but it seems like it blows externally, is that correct?

The only thing strange I noticed about the carbs is that on one of the bowls, the the release valve screw is puttied in, and I wouldn't be able to release any fuel if I had to, but when it was running, it didn't bother anything.
Click to expand...
Did you soak these carbs in Berrymans Chem Dip or something of the like to clean them? Just shooting spray in em doesnt work man. You have to assure that they are completely clean..every little passage is spotless, and the only way to do that is to dip them for 12 hours or more...
If you DID do that then lets go thru this again... Im not super familiar with the 450s but I will give it a shot. The FUEL line, the fat one, goes to the T in between the carbs. The number TWO carb has a hose barb on it for the vaccum line for the petcock. The line should go straight from the carb to the petcock..no stops in between.. any hose barbs on the BOTTOM of the carbs if there are any, are simply vents to air...they dont connect to anything...
 
Thanks for working with me on this.....

BTW, here is a link to the diagram of the carbs on my bike...http://www.bikebandit.com/suzuki-motorcycle-gs450lg-1986/o/m6037

So, there's a total of 4 valves between carbs, the 2 lower ones with a "fat T" connection is connected to the fuel line. The other 2 upper ones are connected to eachother through smaller hoses and a smaller "T" connection to make one hose. Earlier in the post, people said this connects to air.

As far as the cleaning, they were definitely soaked. I could always try again.
 
Sounds like those carbs are driving you mad!!! A good way to confirm the passages are clear is to buy some canned air like those for cleaning computers and with the nozzle attached blow some air though all the small passages in the carb and find out where the air comes out. Compare each carb with the others to make sure they are all blowing air out of the same passages equally. There will be some variations with the vent passages depending on carb placement and whether it has a vacuum line or not. If all is well they should work and you've now learned which passages do what. Good luck with them.
 
With the carbs off the bike and the float bowl off
Spray carb cleaner into the two jets on the filter side of the carb. The left screw in jet (pilot air jet) will blow out the pilot jet and the one on the other side (main air jet) will blow out the main. These jets are what sucks the fuel out of the float bowl and into the engine. If the jets or ports are clogged in any way you will not get fuel or limited fuel.
I have only been able to get these clean by a good soak in Berrymans or a good carb dip.
Also if you have the pilot jet rubber cap there is a port connection the main jet passage to the pilot jet. This where the carbs divert the fuel from the main to the pilot while the jet needle is blocking the main. Make sure this is clear also.
 
Sounds like I need to do an extensive cleaning again. I really thought I took care of all that, but I'll give it another shot.

Do my connections sound correct?

Also, If all is clean including passages, I should be good to go right?:)
 
You must log in or register to reply here.
Back
Top