You might do a leak-down test again and see if its changed. You can also spray carb cleaner around the cylinders, gasket surfaces, head, stator, etc and see if it bogs when you spray it. If it does, you have a leak somewhere. Start swapping parts side to side and see if the problem jumps to the other cylinder. Swap your carbs side to side and see if the other side goes lean. Swap plug wires, reeds, etc.
- Jared