I did the, almost, same couple days ago. Only I bought a second scale (on sale 16USD) and put it on both at the same time.
Did the weighing twice and got 1kg difference, so the scales arent THAT precise.
As to the weight distribution (Ive just asked this question on another topic - what is the f/r bias on a standard SP1?)
Your difference is less that 2kg - thats less than 1kg front and rear out of little more than 100kg - so little less than 1% - which if you weight multiple times might change around.
Why the rear is heavier than the front? In your case it's not much - but remember behind the engine you also got the tail, massive swingarm, wider rim, begger wheel, chain, exhausts, compared to in front the forks and smaller wheel and rim.
You got 50,5% rear and 49,5% front - its pretty damn close.
Ive got 49,9% rear and 50,1% front - still pretty damn close.