..."i change the oil every 2k with napa 15/50 full synthetic"
Well that's a waste of good oil and money. Hell, even dino oil lasts that long or longer.
Weather its a waste of money or not is a matter of opinion, how often a dude wants to change his oil is up to him, I have road bikes for almost 50 years, if you count the mini bikes and scooters, that makes 25 bikes, and I don't think my oil has ever went 2000 miles on a change, with any oil, I personaly don't go in for that 5, 6, 7, thousand mile oil changes, but I won't fault those who do, its there bike, theres no way in hell you can tell me that oil is still doing its job when its got 6 or 7K miles on it,and I don't care if its so called full synthetic or $1.50 a qt Wally World special, what I mean is how do you know what oil is in the jug other than whats on the label, other than it feels like oil,...........you know that gasoline all comes out of the same cross country pipe, no matter who's pump it comes out of