Where is the engine oil drain HD 1998 sportster 883?
Lay down on the left side of the bike, look underneath where the
frame and swingarm meet, on the right side you'll see a hose
clamped perpendicular to a plate. That is it.
If the bike has been sitting and the oil level seems low you may
need to drain the sump. It is an Allen screw (6mm I think, I just
pulled one during a rebuild the other day and no SAE size fit) on
the bottom of the case. It will be flush and might not be readily
visible if the area is dirty. Avoid using this drain.
If the oil was dramatically lower than when you parked the bike
and there is no visible spot where it leaked, run the bit a touch
and see if it rises. Sometimes the oil drain siphons back into the
engine during storage.