The design of the kickstart seal assumes that there will be no endfloat on the kickstart shaft. This is rarely the case and means that oil weeps from the kickstart shaft. You might be able to limit the weep by fitting a second o-ring, or you can fit a rubber grommet between the casing and the kickstart lever (a 20mm cable grommet fits perfectly).

The cover should fit easily (with a bit of jiggling). Do not use force. If the cover won't go on, it may be fouling on the kickstart spring or the gear change pawl.

The gear change should operate freely. If it binds, take the cover off again and check that the gear change pawl spring is correctly placed.