Hi, i was cleaning bike after 250 mile ride in hot weather the previous day ,and on the primary side of bike ,from passenger footpeg to rear axle covers was covered in a blackish oily residue,could this be from tranny vent or what do you guys think,any ideas,thanks

 

i would begin by inspecting my final drive belt. Poor alignment of the rear wheel or front belt pulley could cause wear on the belts edges.

 

That was the first thing entering the little cubbyhole where I store my braincells in too.