After reading all the oil posts,and the forum regarding this issue...I'm going to go with Amsoil 20/50 in the engine and the primary....and Amsoil 75/90 in the trans (I do feel a tranny should have It's own grade of oil....summat to do with the trade I work In)

I don't know whats In at the moment......does this seem a good way to go?

After reading all the posts.....It's doing me f**king head in![&:]

 

I know how you feel Tommo,there's so many views on what's best to use that your brain goes into melt down trying to decide for yourself the right stuff to go with.

i'm with you and going down the Amosil 20/50 route although it seems the same oil grade is ok for the tran's as well[:@]

 

Exactly what I use, I also use the amsoil oil filter EaOM134C for my 041200C

 

amsoil=good stuff.my nightster ran definitely cooler,tranny smoother also.

 

Still feel engine oil Is to light for the tranny.

 

The problem with that is that it goes into the primary. So there are other considerations there besides the tranny gears such as the clutch and primary chain. Is 75/90 good for tranny gears? Yes. Is it good for the clutch or the primary? I have no idea.

Besides Harley oil the only other oil Harley recommends is 20W-50 diesel oil. That would be my first choice. As for oil, just run oil in there that's the proper weight. Overall, I don't think it makes a damn difference.

 

So the primary and gear box share the same oil?....This is where it gets confusing for a new Sportser owner.....3 holes= 3 oils?......so It' 20/50 everywhere?

 

On the big twins there are three holes: engine, primary, and tranny. On the sportsters there are two holes: engine and primary.

 

20/50 all round then...to busy riding It to investigate properly...and to lazy to read all the books. right now all I have to do Is find a place with the oil in stock!

 

Tommo....Once you have done the change. Let us know how the bike runs ....