When my old 2-stroke started running rough, I figured the carburetor was gummed up. I went down the rabbit hole of carb cleaners — sprays, soaks, additives — and finally settled on a spray carb cleaner safe for outboards.
I like the ones with a straw nozzle that let me hit all the small jets and passages. After a couple sprays and a little patience, the motor idled smoother and started easier. Not every carb cleaner is equal, but the marine-safe brands have worked best for me