I cant help with the cut off measurement for the Scorpion as I havent got one. Loads of people on here have though. Might be worth having a search as I suspect this will have come up before. Failing that give Scorpion themselves a ring and ask them.
Where you want to measure from is the weld and then cut it from there, but cut past the weld towards the rear of the bike not in front of the weld.
I've highlighted the weld with an arrow in the picture above.
HTH