Just let it drain overnight if that is possible. Then maybe change the first fill of Royal Purple out sooner than you normally would and you should be set. That is all I did when I went from Merc to Amsoil in the past and had no problems.

Royal Purple will mix with the Merc oil. They dont recommend any cleaning or long draining period. You can if you want, but it is compatible, so if you choose, you can drain and fill and go boating! Wouldnt hurt to drain it early, but no real need to.

Hope this helps.
Dick

Helps a lot .Thanks guys !
Darren