How would i go about getting the sand out?
I know the top end has to be rebuilt but im not sure about
the bottom end can anyone give me some advice

 

This is what I did to a 250r motor that had sand and piston part's in it,when I got the jug off I checked the crank bearing's then filled the bottom end up with kerosene moved the rod to turn the crank,I then let it sit fir five min. then took a shop vac. with a small hose taped to the end I vacuumed the dirt and piston piece's out with it.I repeated this 5 time's just to make sure and it worked...