first tesla coil

Hi this is Chester Lowrey I just built my first tesla coil and here are the

powersupply:    12kv 30ma NST
cap:    2x 5" by 5" plate cap with 60 insulating layers each ten sheets of 4
MIL         polyethylene  immersed in mineral oil. uf ??
sparkgap:       8 coper pipe gaps 
primary:        7 turns 1/4 copper pipe 18" diameter flat pancake
secondary:      6" by 24" PVC pipe wound with 24gau copper wire 
all conections made with 10gau insulated wire.

from this description what do you think about it's performance? all i can
currently get is 5 inch sparks at the most. my thoughts are that the
transformer isn't big enough.
but would it work better if i use a smaller primary and secondary?
transformers are preatty hard to obtain when you live in hawaii and are only
15yrs.  i just built the cap this weekend and was expecting better results
than with my 7 bottles but spark gained 1' at the most 

        well i would greatly apreaciate any help/comments PS. sowrey about
the spelling hope you dont mind