07 Ultra with 1300 miles completely stock. During a ride yesterday I was told by other riders in group blue or black smoke was coming out of left exhaust also a little smell. On inspection it was smoking from left side only also left exhaust looked oily and right did not. After breakfast continued ride smoke stopped but still a little oil smell ( I think) and pipe is cleaned itself up like the right. Mostly mountain ride at about 3,000 to 4000 elevation. Before smoke started we were stuck behide logging trucks. Had to ride in first gear and very slow.

I am taking in for true duals today and race tuner but was not sure if I should until smoke issue resolved. Map problem maybe ? Hopefully not a engine problem. I did change oil to syn-3 before we left 960 miles on ODO. Or maybe duals and re-mao might fix ?

Any ideas ?

 

The exhaust flow on the left side isn't nearly what it is on the right side....take you hand (while the bike idles) and feel the difference between the two. The exhaust that comes out the left side is mostly from pulse waves the exhaust makes and back pressure. Here is what I mean....the exhaust flow (mean flow velocity) travels between 280 to 300 feet per second....at this speed ther is NO way the hot expanding gasses can make a 90 degree turn and come out the left pipe. When those gasses meet up with the juction from the frt pipe a pules wave is made and pressure is built up from ithitting the bottom ofthe pipe which sends some of the exhaust back up the rear pipe and out the left side....this can only happen when the rear cylinder is done with the blow down cycle. Now where the oil is coming from....thats puzzling. It could be from the high rpms while you were in first gear behindthe logging truck. Keep an eye on it as you put more high way miles (normal high way MILES).....lol

Good Luck