Suzuki 2 Strokes

73 GT550,
On occasion after riding the bike, I will notice a bit of really black thick oil drop on the garage floor under the pipes. I have several bikes and try to keep them all exercised so in many cases the rides may just be a 15-20 minute ride. Is it possible I'm just not getting the GT good and hot to burn off any residue. The bike smokes a bit on start up but clears out quickly. It runs great, starts on the second kick, just wondering what the oil drop issue might be?
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Yes the thick oily substance is a mixture of unburnt oil,carbon soot and water caused by condensation on the inside of the pipes. There are little drain holes in the bottom of the pipes so it can escape. A really good blast will blow it all out the back. This is common with owners who winterize their bikes and think its a good idea to start the bike and rev it for a few moments then switch it off.

Pressure wash inside pipes, and clean them out well.