I don't have the part that you need, but maybe you should also look into what may interchange with that from other "clone" brands or other OS .46 engines. I dead a lot of classifieds and such and just don't ever recall seeing much in the way of parts for these being offered up by individuals. Randy Smith may have it as he stocks some OS parts. There is the place in Japan that acts as a clearing house for R/C engine parts, R/C Japan or something like that, and they have good prices of parts but shipping is pricey. Good luck with the search.,
Dan McEntee