98 GSX Ltd. Starving for fuel at higher RPM

[Tri_CityMJ]

Hello ALL,
I am having a fuel issue with my 1998 GSX ltd. Starts right up , runs fine until about 35 MPH or 1/3 of the throttle. If you punch the throttle it will die. If I slowly keep priming the plunger(primer) up and down it will get right up to 60MPH. So here is what I have done in the 2 months I have owned it. I first changed all of the gray fuel lines, removed and cleaned out the fuel selector valve, replaced the plugs, removed and rebuilt the dual carbs.I am using non ethanol fuel. Is it an air issue? maybe from the aftermarket primer that someone installed? Im not sure where to go from here. I had a guy look at it and he said one side of the coil was weak? Im not sure if that would affect the fuel delivery issue. sounds like another issue to me. Anyway I could use some help. Thanks MJ

 

[mikidymac]

First of all stop running it as it is lean and will damage the engine.
Cleaning the fuel selector doesn't work and they need to be replaced.
Clean the fuel strainer and install a new square o-ring on it.
When you rebuilt the carbs did you.......
1. Use genuine Mikuni kits?
2. Replace the needle and seat?
3. Change the springs in the carb?
4. Check pop-off and leak down?

 

[Tri_CityMJ]

1.yes
2.yes
3. yes
4. yes
I was thinking that replacing selector valve and the primer kit(hoses and all)
and see where that leads.
Thanks for responding!

 

[mikidymac]

If it has an accelerator pump on the carb I have had one bog really bad from idle and almost die when it wasn't working. Just verify yours does but this should not affect wide open throttle.