Rookie Carb Question

[pnwesside31]

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.

[chef1366]

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?

[pnwesside31]

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?

[Don-lo]

yes, that sounds correct from here

[pnwesside31]

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.

[Dave8338]

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.

You will not regret that decision...

[pnwesside31]

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."

[Sandy]

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.

[LarryA_Texas]

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.

[pnwesside31]

Thanks for all the feedback. An suggestions on good sights that sell petcocks?

[chef1366]

Thanks for all the feedback. An suggestions on good sights that sell petcocks?

http://www.z1enterprises.com/catalog.aspx?pid=SM000

[pnwesside31]

Thanks. That site is awesome!

[pnwesside31]

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?

[TheCafeKid]

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?

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...

[pnwesside31]

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.