GPZ1100 Fuel tank - Fuel transfer from unused tank side

 My GPZ1100B1 fuel tank has a Pingal   tap on the LHS, the problem is that my bike starts to surge when the fuel level drops to around 75% because the fuel on the RHS can't transfer over.
There is a spigot on the bottom of the fuel tank on the RHS but I don't know what this is for. If it is for the fuel transfer how is it used so the fuel still goes through the tap??. Any ideas would be appreciated.

Use short pieces of fuel line to connect the LHS and RHS spigots to the L/R sides of a tee fitting. The tee should be free-flowing in all directions.

Use another piece of fuel line to connect the third part of the tee to the Pingel. Done.

The B1 tank isn't "divided" left/right. (well, mine wasn't)
I know this because I modified my B1 tank to accept a standard Kawa vacuum petcock.

 

 

 

The second spigot is for the "excess" fuel to return from the electric DFI fuel pump. 
You can attach your Pingel petcock to either side.

Something else is causing the problem that you are experiencing.
Perhaps the tiny breather hole in the gas cap is blocked?

H.

Thankyou both for replying. You gave me something to think about.
You are correct the RHS spigot most likely is the injection return.
The fuel cap I checked by opening it up when I felt the surge, so that's not the problem.
I'm starting the think my carbies need more fuel tank pressure to activate the needles (I'm running ZRX1100 CV carbies), it appears my idea of fuel staying on the RHS was NOT correct.

Come to think of it my other bike the FJ1200, I took off the fuel pump changed to the smaller seats (fuel pump requires larger inlet seats) thinking the pump is not required and I had the same problem so I went back to the fuel pump.

If it comes to the crunch I'll fit a fuel pump, although I'm not sure what pressure would be required - any ideas????

Fuel pressure with carbs needs to be low so it doesn't overpower the floats, an adjustable regulator would allow you to dial it up until it floods then back it off again. However to be honest it shouldn't need a pump (does the ZRX that donated the carbs use a pump ?)

I had a ZRX1100 and I'm certain it doesn't have a fuel pump, The tank is about the same size etc. 
I'll have to do more homework on this, thankyou for your input

Just some considerations Bozo. Yes as mentioned, correct cap ventilation of course. When You say surge, under what conditions? Is it at an even slight throttle, like going on fairly flat terrain and feels like it is "hunting"? Or WOT and missing out and stumbling? You mentioned something about those Float needle seats or You call them Inlet seats. Actually introduction of a fuel pump will require Smaller inlet seats, not bigger. And you'll find changing those seats doubtfully would be required. And if so, gotta know how to do it, they are pressed-in on those CVK Keihin's. And no replacements that i'm aware of off the shelf. I pull them to get behind and remove crud but a special technique is used. A couple versions shown, note length differences.    

Opps that's what happens when I sniff cheap fly spray, you are correct smaller inlet seats for fuel pump. I just checked, unlike some carbies the ZRX seats don't appear to come out nicely. 

Reference to "surge" it feels exactly like its running out of fuel with 25% of fuel left in the tank. I'm running out of ideas. I initially thought it was the tank design but that was not the problem.

First I'll take the tank off and make sure the fuel drains fully through the petcock. Once this has been done I can look at the carbies. I'll keep you posted.

Thankyou for your help

 

Again, thankyou to all that helped. It was my fuel cap after all. I was amazed at how good the pingel tap was, it basically pored the fuel out. 
I filled up the tank (to check capacity of the tank - Fuel just touching the neck = 20,75ltrs / 30 C. The fuel started to surge around 14 ltrs and at times it stopped until it gasped for air, finally draining fully (with the fuel cap open). While empty I checked to ensure the tap screen is clean.
The cap I have is a knock-off, the seals/ orings were a bit too tight so I changed the suspect for a thinner one and the surge appears to subside until empty with the cap down. CROSS fingers.

Merry xmas and Seasons greetings to all