It is common, especially on H2, for a puddle of oil to appear under the bike after sitting. This is caused by a pressure build up in the transmission case. There are some fixes that can be attempted to cure this problem:
-Remove the O-ring on the dipstick
-Drill a small vent hole in the dipstick
-Turn the vent nipple upward and attach a short vent tube
The H1 has a small hole at the rear of the engine without a nipple. This hole can become clogged and cause excessive pressure to build up resulting in external seal leaks.
The most common source of 2-stroke oil inside the pump cover is from aluminum banjo bolt washers not sealing. They are designed for one time use and will leak with repeated use. The best fix for this is to use Parker Stat-O-Seals (1/4") or Dowdy washers on each side of the banjo fitting. These have a "rubber" seal and can be reused. A small amount of case sealer applied to the seal can help.
Avoid overtightening the banjo bolts to correct leaking as they will easily strip the pump housing or break.
Another reported source of oil leak on S series is through a tapped hole in the case behind the points plate. Fill the hole with a short 6mm screw to remedy.