Can I find out the details of the person who owned a motor bike in
England in 1952 (circa)  I have a photograph of my mother sitting on
this motorbike and the rego number is KJ0917.  I think the bike was
owned by Mr Frank Cole.  It is his details I am looking for - for
family tree

greenmaureen,
The specific answer to your question is no.

?it's not possible to access the DVLA (1) records unless you're in the
Police Force or similar, however a call to DVLA will usually reveal
whether they hold a computer record for the vehicle?(2)

However in view of the above quote (& the page where it is taken from)
it may be possible to narrow the search area down to a location if you
email the agency; explain what you are doing, ask if they have any
record of the registration number and if so what information can they
reveal. Even if they have nothing, ask if they can specify the
county/city such a number was issued from.

Persistance is necessary on your part to explore all possible avenues
and as a introduction on how to proceed with genealogy research in the
U.K  refer to referance no 3, with a ?useful links? page combining
many source material bodies, for an enquiry such as yours.

Referances:
(1) Driver and Vehicle Licencing Agency 
http://www.dvla.gov.uk/contact/dvla_custenq.htm
(2) Development of British Registration Numbers
http://www.fofh.co.uk/tech/rego.htm
(3)
http://www.kent.gov.uk/sp/kentregserv/geninfo/trees.html

Kind regards.
gfmaster

Greenmaureen,
The reg is probably KJO 917, rather than KJ0 917 ('O' rather than
zero). According to records it was was first made available in 1946
with the original vehicle licensing office for this letter combination
being Oxford C.B.C.