2011 Limited gas smell in oil

Discussion in 'Touring Models' started by NewtoHD, Sep 2, 2011.

  1. NewtoHD

    NewtoHD Member

    Had a stage I installed by the dealer with a SESPT dyno tune at the 1000 mile service. From the beginning, I have had a exhaust pop when up shifting when I let off the throttle. Now at 1300 miles, I checked the oil and noticed a slight gas smell on the dipstick, the oil does not seem diluted but Syn3 is kind of thin to begin with, and it has a slight darker color than new. I also have a slight black sooty color in the mufflers, no raw gas smell in mufflers. Bike runs OK, other than my poor dyno numbers (previous post). I stopped by the dealer today and the service rep said to drive it, this is normal. Do I drive it or look for problems?

    Sorry if this the same old song on a different day.
  2. btsom

    btsom Active Member

    It is a fact of life that there is slight blow by in any piston engine. The same stuff you see on the muffler outlets also blows by the piston rings and gets in the oil. Beside lubricating and cooling, another job of the oil is to hold these contaminants until the next oil change. A small amount of this soot will settle out and stick on the internal surfaces of the engine. The only time in the life of the engine when the internal parts are NOT pre-coated with blow by contaminants is during that first 1000 miles. The oil stays clean looking for a long time, but all the while the contamination is accumulating. After that first oil change and on all changes after that, there is already a layer of stuff on the inside. The new oil with fresh detergents will pick up some of the stuff quickly, beginning with the first start with the new oil. From now on, it will be NORMAL for your new oil to look dirty faster than it it did in that first 1000 miles. Harley knows this, the folks that make engine oil know this and the oil change intervals take this into account.

    In addition to combustion soot blowing by the rings, on the compression stroke, a small amount of gasoline gets by. Water is also a normal product of combustion and it also will work its way past the piston into the oil. If you make lots of short trips, never getting the engine and oil up to full temperature, that gasoline and water won't boil out and it will slightly thin the oil and it can be smelled on the dip stick. If your normal duty cycle is more than 10 miles or so, boiling the volatile items out of the oil is pretty much automatic. Just as your clothes will smell of smoke if you are near a smoker, your oil will smell slightly of gasoline from the blow by stuff that it is supposed to hold. Long story short, what you are seeing is normal.