I've never had that kind of luck with the additive carb cleaner types especially after a bike has sat unused for years with gas turning to brown varnish. To properly do it right, you need to take the carbs off the bike and totally disassemble everything inside the carbs including all jets and soak them in a carb dunk tank like Berryman's. Then, blow all passages free and clear with compressed air before disassembly. But what do I know....... have owned 35+ bikes, do all my work, and have restored several bikes from the ground up??

Gary- it sounds like a nice bike. Good luck with what route you take with it!
Gary, get your self a bottle of Yamaha Carb cleaner and an IV bottle (seen people you soda bottles) run the hose to the fuel inlet for the carbs, crack the float bowl drain screws until you see the Carb cleaner start to come out, do this to all four carbs, let sit for 45 mins, and repeat and let sit for 10 mins. Drain all the Carb cleaner, connect your fuel tank with FRESH gas with just a few oz of Carb clean and ride, this can be done with the carbs still on the bike. Also don’t for get to change, oil, plugs, check coolant, tires, lube chain if its still good, and lube cables. If that’s the route you did decide to take
I was shown that by a corporate Yamaha tech while at a Yamaha seminar , tried it on a customers bike and then tore the carbs apart to check and was surprised by how clean they were, never dipped a Carb since.
But what do I know...
I have only owned 14 bikes all of which were built from the ground up, street bikes, Harley’s and choppers
Only built 50+ 2 stroke stroker motors which included shaping the bowls and squish band while at (RPM's in Covina) built all the magazines test bike and ran the dyno
worked as a A tech for a Suzuki dealer for 2 years
worked as a A tech for a Yamaha dealer and service manager for 8 years
and while at the Yamaha dealer also work for a privateer race team where I built 6 race bike from the ground up, suspension, motor you name and did part of the AMA circuit in 600 super sport and formula extreme for a few years as the only crew member besides the rider, where the races we did attend we were consistent top privateer.
then the Harley’s have customized 100's and built up wards of 20 full custom choppers/ pro-streets, and a few original Harley Pan Heads. one of the choppers I built was on the cover or easy rider and another featured in iron horse
But hey what do I know...