Had a customers Comet with a 600 top end kit on it.........we installed a 36 mm Mikuni and after there seemed to be fuel dripping from the clear overflow drain lines......I think the owner ended up lowering the float level to fix it. But I think if the carby hangs slightly lower at the rear, this may cause the problem, as I don't think they like that angle too much. Didn't they originally come factory on Yamaha XT/TT 500's.