Fuel mixture

[alphabet]

Hello
I have recently acquired a 1999 US-built 15HP 2 stroke, serial 0G846299, family XM9XM0016210. Starts and runs very well on the fuel that was provided, but I am unsure what the fuel/oil ratio should be. Would someone please be kind enough to advise? Also, is there somewhere that I might download a copy of the user manual for this motor?
Thanks!

[boats.net]

You can purchase the owners manual on boats.net at the following link. Mix ratio should be 50:1

10104040 - OWNER'S GUIDE $24.52