Chuck wrote:
If I am *not* an A&P and I own, but didn't build, a homebuilt aircraft that
has an experimental certificate, am I allowed to repair or inspect the
aircraft and sign off the work?

Anyone can do any work on an Experimental-Amateur Built aircraft, and
sign it off. The only thing that requires a certificate to sign off is
the annual condition inspection. That inspection can be signed off by
any A&P (IA not required), or by the individual (usually the original
builder) who holds the Repairman-Amateur Built certificate for that
specific aircraft.

Hope that answers your question.

Regards,
Ken Balch
RV-8 N118KB
EAA TC & FA