7mm. The bearings are 13mm x 7mm and 14mm x 7mm.
Silver lining: Boca has the bearings I need, in stainless/ceramic, with and without metal shields, made to ABEC 5 tolerances. And the empty crankcases I ordered showed up, and there are no casting defects. (I had one with a casting defect in the exhaust, and it took me weeks to figure out why there was so much oil all over the engine, because the defect was so small.)