Yes, only 1 drain plug, and right in the middle of the case. And you have to use oil that's made for wet clutches. Motor oil will destroy your clutch. There are several brands of 2-Stroke case oils. Motul, Klotz, Amsoil, Maxima, Yamalube, bla, bla, bla. There are also different weights of oil. You choose which weight is appropriate for the temperature where you ride, and how much viscosity you want. The list goes on. Me personally, I just use Castrol ATF Type-F.