I can assure you carb needs further cleaning. Carb-sprays no longer work due to removal of chlorinated compounds. Pee actually works better since it has ammonia.
Have to completely disassemble carb down to every last nut, bolt and individual component. If it can be futher disassembled, it needs to be done.
Then physically scrub all parts and all petrol passages form end to end with scrub-brushes using PEA-based fuel-system cleaner.
http://n4mwd.blogspot.com/2013/10/se...-passages.html
Poke out all bleed holes in jets, emulsion-tubes and carb-venturi with matching size soft copper wire. You'll find it pokes out little plastic dried petrol plugs like little grains of sand. No way that's being dissolved by any kind of solvent. Make sure you re-assemble needle-jet/collar with tapered end facing needle. Micro soda-blast everything.
Many expert mechanics with decades of experience have had to pull carbs 4-5x for ever deeper cleaning before they got it factory-fresh clean and bike ran like new. Best to do full restoration first time around so you don't have to keep on pulling them.
As for petrol-flow into carbs, best to measure and get some numbers. Then you'd know for sure rather than trying out different things without knowing before & after measurements. Bottle is fine since any flow issues would affect both carbs evenly. Unless you need to replace fuel-rail O-rings, which might affect one side more than other, so should be done anyway. Also replace all rubbers such as float-valves, flow-bowl seals, maybe even slide diaphragms as needed.
