Yep, oddly RS cases are what is banned under the F250 rules, RS anything else (except arguablely the carbs if they're listed as F3 parts) is fine.

"If you race a TZR or NSR - because they share so many parts with pukka GP bikes you must use the frame, crankcases and same size carbs as the road bike - hence TZ engine, carbs or frame are not allowed likewise for the RS Honda. But you can fit barrels ignition etc."
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