Engine Size

.10 – .45 cu inch
/ 2,5 – 7,5cc
.45 – .90 cu inch
/ 7,5 – 15cc
.90 – 1.50 cu inch
/ 15 – 25cc
1.50 – 4.80 cu Inch
/ 25 – 80cc
4.80 cu inch
/ 80cc+