Make sure the woodruff key on the crank is facing straight up. leave the guides and tensioner of for now. get the chain on making sure the mark on the chain lines up with the mark on the crank sprocket.
then lift the chain off one of the balance sprockets and turn the sprocket until it lines up with the link, then repeat for the other one.
As long as all the links line up with the marks on the sprockets thats all that matters