Part 43 to Title 14 which is frequently called the FAR describes the required maintenance entries and tells the certificate requirements to make the repairs and return an A/C to service.
Actually....FAR part 43 does not regulate what logbook entrys are required for an RV because the very first paragraph of FAR part 43 says "This part does not apply to any aircraft for which an experimental airworthiness cetificate has been issued".
That is the reason amature built aircraft are issued operating limitations that have requirements for the intervals of the condition inspection (amoung other things), and what level of certification is required for signing it for return to service.
The operating limitations do stipulate the condition inspection sign must reference appendix D of FAR 43, as a guide for completeing the inspection.
The local FAA airworthiness inspector in our area says that the adminisration interp. is that any maint. activity should be put in the log book (though their is no apparent FAR that I am aware of that requires it). His position is that no disiplinary (or otherwise) action would ever be brought against an RV owner for a log book entry that he made, but that action could be taken for entries "NOT" made.
I usually recommend that any activity completed that required tools (remove an inspection cover, Cowl, Wheel fairing etc.) be entered in the log book. Anything that doesn't require tools or is cosmetic, like add air to tires or touch up paint scratches, need not be entered in the log.
If anything ever happens that would cause FAA personel to look through your log books, and all they find is oil changes and annual condition inspections, they would be very suspicious. If they see more entries than typical, they would likely consider you contiencious about your maintanance. IMHO
Scott M