I'd rebuild the carbs on the motor that hesitates, it's probably a lean carb causing that. While inside I think a metering needle and seat replacement is the way to go and maybe the rubber metering diaphragm if it's not nearly as soft as a rose petal, they can get hard and start oil-canning, causing rough running and flooding. Probably yours is still soft, is my guess. I think you'll find trash in the tiny basket type fuel filters inside the fuel inlet, and gum deposits in the bypass/transition ports, remove the kidney shaped metering plate inside the fuel chamber under the rubber metering diaphragm and shoot a good amount of carb cleaner through the two brass jets, watch inside the carb bore as the carb cleaner shoots out the holes, it should be a strong stream not a dribble.
Anyway, maybe you already read the carb sticky. A lean running carb can damage your engine quickly so I'd take care of this issue, bad idea to run a 2-stroke that's having carb issues, including stale fuel. BTW, I'd stay away from adding anything to the fuel besides stabilizer, additives aren't likely to solve any problems and they can interfere with the fine lubricant balance.
Also, make sure you're using the correct oil, it needs to be API-TC rated including the low-ash package, there are some oils being marketed as API-TC that don't have the low-ash additive package, sometimes they're called universal and can be used in TCW-3 motors, stay away from that stuff as it doesn't have the low ash package you need. This motor runs hot piston temps, that's why it needs the ash package.
There are several different size metering needle seat orifices dependant on which motor and carb setup you have, make sure to get the correct size or it won't work properly.
