Check out pat656's comment here:
I have a 2006 Moomba Outback direct drive which I wakeboard behind and have 2 540lb sacs on each side of the engine. Where do I need more weight (ie bow) and how much.
Then get Skier's Choice Product Manager Matt Brown's professional take on how to weight "his" boat:
I assume he has the optional ballast bag under the rear seat. That
would put his total ballast weight at approximately 1300 lbs (300 rear
seat, 500 each side of engine). Obviously from the factory we can not
recommend that you use more ballast than coast guard capacity. But if
he were to add more weight he needs to decide if he wants his shape a
little steeper or a little more mellow. If he wants it a little steeper
then try adding about 400 lbs to the rear ski locker. If he wants it a
little longer and more transitional then add 400 lbs to bow in walk way.
If he likes his shape but just wants a bigger wake, try adding about 300
to front and 300 to back. Be careful and do not overweight the boat.
The more weight you place in the boat the harder it is to drive. Always
remember – Safety first!!
Also, check out the video of Matt's epic Raley crash on last year's boat tests. Yes Matt, safety first.