Named it that for a reason.

I have searched far and wide on this topic but I am at a stand still.

I have added higher bars and adjusted my clutch cable to accommodate. Thought there where some other issues so I tore apart the primary for the heck of it.

All looks good and I went to out the oil back in it. !!!??? Store was out of the Mobil 75w90 that I used recently so I grabbed vavoline 75w90 (not synthetic) for 4 days I have researched oil viscosity and many other forums. While many use the Mobil 75 instead of the recommended 20w's I can't stop but wonder a couple things.

1. Is valvoline trash for bikes? Says it's rate at API 4 and 5
2. Should 75w90 not be used in sportsters since the clutch and tranny us sharing oil
3. Could this be why it has been hard to find neutral (while warm) and slightly hard shifting.

 

I think some gear oils may be potentially damaging to brass and copper parts. I know that Mobil 1 is supposed to be safe, but not sure of Valvoline. You can also run BelRay Sport Transmission Oil, it's made for the Sportster and decent priced.


John

 

Motor Oil and Gear Oil viscosity is measured on 2 different scales. A 20-50 motor oil has roughly the same viscosity as a 75-90 gear oil.

 

I just use Harley Formula Plus fluid.
The manual calls for it , it's not even expensive.
I get fancy with my engine oil.
Mick