I suggest having fewer classes.  I think it would be great if there were fewer classes with longer motos more like the GP races.  I was thinking maybe something like 20min plus one.  Maybe just have a big bike A, B, C and D class just one vet class.  I'm not sure what to do about mini's.  I'm not a parent so my opinion doesn't mean squat <!-- s:D --><img src="{SMILIES_PATH}/icon_e_biggrin.gif" alt=":D" title="Very Happy" /><!-- s:D -->  Also, at the Co Fair this year they used a big rubberband as a start gate.  It worked pretty good. If a start gate is out of the budget for a while, you might consider it as an alternitive.