If someone is able to help out in any way with this problem, it would be greatly appreciated.

Back at 17,000 miles on my bike, I went through the stage of changing my 20W-50 synthetic oil from Harley (the gray looking bottle) to regular motor oil from Castrol GTX. For a long story short, I didn't want to continually worry about adding more and more synthetic oil to my machine that kept on eating it all away. Right after the change over to regular motor oil, remember there is currently Castrol GTX in it right now, I begin to hear this tapping noise when the RPM's become more and more higher. More of a tapping noise at the top end that I can clearly hear because I have a wonderful windshield on my bike as well. Was using Castrol GTX motor oil a bad idea? Should I have used the Harley Davidson motor oil instead? Now, I'm at 20,000 miles and it's time for yet another oil change and I plan to stay with regular motor oil. The thing is, I asked someone at my local Harley dealership and they stated something like this. The reason for the tapping sound that I am getting it due to the air pockets that is formed by the motor oil, and that I should have used a diesel based oil, like Harley oil, instead of motor oil designed for a car. Is this correct? Am I getting those tapping noises from air pockets being made from the motor oil? Or is this simply something where I need to get my top end of my engine redone because of the high mileage?

Again, if anyone has a suggestion or a flat answer, it would be greatly appreciated.

~Thank You, Joshgt2

 

you shouldnt have to have the top end done at 20k, imo.
wonder whether the synthetic to dino to synthetic did something, but i doubt it.
my guess is that what you are hearing is normal for your bike.
i would also guess that you started hearing this after you put on the windshield because you hear a lot more with the windshield than without it... experiment and take off the windshield; go for a ride and see how it sounds

 

Already did the experiment of going for a spin without windshield and obviously I don't hear it as much. But I got the windshield at around 13,000 miles on it, and didn't notice a thing. What I think I'm going to do is simply go about my oil change for this 20,000 mile mark with the Castrol GTX, since I bought 10 quarts worth of it at the same time and I don't want to be like BP and waste it, so I'm going to try that. If the problem pursues, for maybe another 1-2,000 miles then I might look into Harley regular motor oil. I'm still trying to research everything before I make a final decision though

 

Regular and synthetic oil are compatible. Mixing the two will not cause any problems. Using automotive oil in your engine is safe. Sportsters (Evo) do have loud top ends.

 

The technical manual will tell you to use a diesel oil if you choose to not use the Harley product. Sportsters, as well as all Harley Vtwins, generally have a numerically longer stroke measurment when compared to the bore, and, coupled with, the relatively small area of the crank case, produces an extraordinarily high volumetric pressure differential. Diesel oils, and Harley oil are made for this environment.

Go back to the Harley oil, or consider Amsoil, or Mobil1, or read yourself to death in the general oil section of this forum.

Ps. I don't sell oil, but I ride, a lot................