Beautiful OEM carburetor, clearly marked 20mm on the carb top. It was totally disassembled, cleaned for 60 minutes in the ultrasonic cleaner and reassembled with original parts. Passages and jets blown out and reassembled. Slide moves up and down smoothly, This carburetor is ready to go
Some S90 used Mikuni Carburetors, so please make certain this is what you need for your application
I also have S90 air cleaner under sku 3988