1300 Watts is 1.742627 Horsepower
You're looking at converting that to CC, which is on a VERY sliding scale...
But it could theoretically be...
26.1cc - 43.6cc
HP, Watt, and CC are similar, but different. What you would have to do is take into account every variable of the two things you're comparing.
Load weight, CC, HP, Watt, RPM, Wheel size, Speed, Drive Gear, Driven Gear, Road Grade...
And crunch numbers from there.