I now have 8500+ miles on my FXSTI. I've changed fluids in all three holes 3 times. First at 830 miles with dino, then at 3300 changed to Amsoil 20W50 in all three holes, at 8300 miles with cool weather coming on, I switched to Amsoil 10W40 in the motor, and primary, and put Redline light in the tranny.
Now my opinions:
Noticed a small diff when I swiched to syn 20W50.
A much larger feeling of smoothness came when I put the 10W40 and Redline in the tranny. I noticed some metal specks on the drain plug that I didn't like and personally I attribute it to using motor oil in a gear box.
Then I oiled my throttle and clutch cable last Sunday, but due to crummy weather couldn't try it out untill today.
WOW, everytihing runs smoother, the clutch and throttle are much easier to pull on. ( I was told it was done at the that 1st service at 830...bull) I doubt anyone else will work on my bike except me.
The tranny shifts much smoother, and quieter, and the motor just wants to pull and pull
This is the nicest ride I've ever owned, too bad I went thru so many *** bikes before getting the nerve and cash to buy this beauty.