You using a thick enough oil? Mine was horrible until I switched to 20W50 at the first oil change. Motorcycle oil is like perfume, if you buy the wrong stuff, you ain't getting nowhere with your girl.
-WD

As cheap as oil is, why not? At worst, you'll have bought a couple extra quarts, run some fresh through the bike and cleaned out some sludge.  No harm there. And if you still end up swapping the discs out, they'll be clean! Some Savages (and other bikes) just can't run the factory recommended oil. Production tolerances do vary pretty wildly. I'm pretty sure the tolerances onmy bike are ALL on the loose end of the scale. 10 weight oil, it sounds/runs/shifts horribly. 20 weight oil, it performs like a "well oiled (pun intended) machine". Have had Hondas do the same thing. Some bikes are just finicky.
-WD

Who's do you mean? My bike has less than 13K on it. :'(
A 98 should have at least triple that.  Mine has been a tinkerer's special since day one. It was built on Friday night or Monday morning...nothing has ever worked right. But I have fun anyway. I like to putter around with it, no hurry.
-WD

Mine's a 98, 11,500 miles now.  It sat for a long time when the first owner went into the military.

My neighbor (has a sportster 883 now) bought the bike for $600 with 10,400 miles from the original owner.  He had alot of work done to it, and sold it to me for a grand when he got tired of taking it to the shop.  I like to wrench and play, so I'm in heaven.  He never registered the bike or even drove it very much.  He had the rod bearing and rocker arms replaced the due to gas getting in the oil (he didn't know).

When I re-titled the bike it had 10,600 miles on it.  The original tags on it expired in 99.  That was October '03.

I had to fix several fuel related problems -- petc0ck, carb re-jetting, needle/seat, etc. --  and repaint the bike.  I love the thing.  I wish I could find another one like it.

Mine was orange faded to pink when I bought it.  I like anything that's unusual, and that usually means old like my cars.  For some reason, if everybody has one, I just don't want it anymore (Chevy Suburban being the only exception).  

There's a running 76 iron head sportster 1000 for sale nearby, asking price is 4200.  I'm afraid to offer $2000 for it, cause they might accept.  It's calling my name real bad, and it's a perfect ratty bike.

I've been using 15W50 and it seems just fine to me.