i used rotella t 15w-40 oil. and when choosing a filter i referenced this website http://www.calsci.com/motorcycleinfo/FilterXRef.html
which i found through here http://xjrider.com/viewtopic.php?f=7&t=90
i ended up buying a NAPA gold filter #1365 which is a wix filter, and i use NAPA gold filters on all my automobiles.
BIG MISTAKE!
see this nut with oil filter threads that screws in?
that nut restricts the type of filter i can use (same for your bike?) i have to use a filter with some distance between the sealing surface and where the threads start inside the filter... exhibit A...
i could not get the NAPA filter to screw on completely because the inside of the filter was hitting 1mm or so before the filter seal was seated. even if the filter seal was touching all the way around, i could not give it the extra 1/2 to 3/4 turn to make it seal correctly.
so just because the filter threads, length, and seal O.D. are compatible doesn't mean the filter will fit.
anyone else run into this?
note: i ended up putting my EMGO filter back on. the body of it was crushed slightly by the wrench i used to remove it, but the oil had been changed by PO several months ago and the bike had only been ridden 100 miles or so since then (read: oil was clean coming out)