You might try posting this over in the XRL fourm. i am sure there are some folk with more experience than me.
I had a twin carb. XR 600 but not for long.
But in general:
Fix the leaks.
Next, it sounds like the cables do not have enough slack. Maybe the second carb is open at idel?
96 XR650L, 96 Guzzi Sport, 07 BMW K1200GT,
86 Husky 400 XCE, 00 Husky Te 610 e, 1999 Husky TC610 SM, 2000 Cagiva GC; Google: TX7