Timely topic. I have one of those pulleys, or similar, purchased from Webbike Japan, purchased for the same reason: MC28 motor with PGM II. It appears that the pulley is larger diameter than stock. Sorry i can't offer any first hand experience yet as the bike is not running. RC valve not working traced back to apparently burnt out PGM unit that was unknown history when purchased.

Supplementary question and not wishing to hijack your thread. I am thinking of sending the PGM II unit to 2T Racelab in Athens for repair and refurbishment. Any feedback or experience with their service would be greatly appreciated. The alternative is to buy another used unit from auction in Japan.