After thinking about this, I think that motor has a sight glass over the powervavle, and I don't think that there is one for the tranny oil. I believe the window is there so you can visually check to see if the powervalve is working. It has been a long time since we had ours, so I don't remember exactly. Maybe Scott will see this thread and chime in, he rides an old Quadracer too.
Yours truly, sincerelly, love always, Josh aka The DirtDemon.