This has to be the most basic question, but I can't find the answer and the search function doesn't seem to be working on this site.
I decided to change the engine oil in my 2005 FXSTI. I am no stranger to oil changes having had about 14 bikes in my time, but never a HD. I went for a ride to heat the oil, emptied it out of the tank through the proper drain hole and changed the filter. I noticed that only about 2 1/4 quarts of oil came out, yet the book says, "Do not add more than 3.5 quarts of oil", presumably the maximum capacity. So why does at least a quart get left in the sump? This has to mean that new oil is 1/3 contaminated with the old oil at every refill. There is a small (about 1/4 inch) screw with a hex head set into the base of the sump (right side). I was tempted to unscrew this figuring that the remaining 1 quart would then run out. Should I have done that? (I didn't!). Finally, I know the oil level was correct before changing it and it is OK now, Still I only used just over 2 quarts to refill it.
I guess if there is still 1 quart of old oil in the sump, then the engine isn't stressed by starting for the first time after an oil change and running with virtually no oil for a few seconds while it waits for the new stuff to get pumped through. Is this why?
Curious!
Any advice?
Giles..
I decided to change the engine oil in my 2005 FXSTI. I am no stranger to oil changes having had about 14 bikes in my time, but never a HD. I went for a ride to heat the oil, emptied it out of the tank through the proper drain hole and changed the filter. I noticed that only about 2 1/4 quarts of oil came out, yet the book says, "Do not add more than 3.5 quarts of oil", presumably the maximum capacity. So why does at least a quart get left in the sump? This has to mean that new oil is 1/3 contaminated with the old oil at every refill. There is a small (about 1/4 inch) screw with a hex head set into the base of the sump (right side). I was tempted to unscrew this figuring that the remaining 1 quart would then run out. Should I have done that? (I didn't!). Finally, I know the oil level was correct before changing it and it is OK now, Still I only used just over 2 quarts to refill it.
I guess if there is still 1 quart of old oil in the sump, then the engine isn't stressed by starting for the first time after an oil change and running with virtually no oil for a few seconds while it waits for the new stuff to get pumped through. Is this why?
Curious!
Any advice?
Giles..