• Notable Separator Plate Design Change / Flaw Between the BUELL (03-06) & (07 & up) Style Oil Pumps
• Oil Pump Drive Gear Upgrade 26391-06
• 5 Speed to 4 Speed Oil Pump Conversion
• 07 & up Buell Oil Pump Pics (26357-02B)

Note: Be sure to check the REF section for additional information related to Oiling & Lubrication.

1991-1997 Models - XL P/N = 26204-91

1998-1999 Models - XL P/N = 26204-98
- From the internal P/N changes it appears that this new
… P/N was generated because of a change in the Gear Shaft
… and Gerotor Return set of gears

2000-2006 Models - XL P/N = 26204-91A
- P/N change appears to be related to a fitting change

2007-later Models - XL P/N = 26204-91A(new)
- is different design w/same P/N (How crazy is that?)
- is retrofitable to 1991-2006
- has bottom cover casting P/N 26213-07

Buell P/N - 26357-02B
- same pump as XL 26204-91A(new) but different fittings
- will bolt up but you need to move other fittings over

See these XLForum threads:
http://xlforum.net/vbportal/forums/showthread.php?t=135265
http://xlforum.net/vbportal/forums/showthread.php?t=1738158

• In addition to the upgraded Drive Gear (26391-06), there is also an upgraded entire Oil Pump (first installed on 07-later Sportsters). The new pump reuses the same full unit part number as a previous version, making it difficult & confusing to know to which version someone is referring. The old (& new) part number for the complete oil pump unit is 26204-91A (that P/N first showed up in model year 2000 and used for the older design thru model year 2006).
• The difference between the 1998-2006 version and the 2007-later version relates to the drive shaft, internal Gerotor return & feed gears and the body (which cannot be ordered separately). The internal parts for the new pump design are not backward compatible to the 98-06 pump design.
• The only known external indicator to identify that the 2007 pump version (using P/N 26204-91A) is currently installed is the cover casting number 26213-07 which is stamped on the bottom of the new version.
• The upgraded pump is compatible (and recommended) for use on 1991-later Sportsters.

Here are the internal servicing part numbers from 1998-2000 version and 2007 and up version:

Click on a pic to enlarge.

Click on a pic to enlarge.

Assembly 10)	Scavenger Galley 11)	Feed Galley 12)

Parts 13)	Scavenger Gerotors Installed 14)	Separator Plate spins free 15)

Feed Gerotors Installed 16)	Pump Cover 17)

Note: Since the Buell P/N 26357-02B is the same oil pump as the XL P/N 26204-91A (new), except for the fittings, be sure to take a look at the pictures in the Sub-document above for that model. It shows some of the measurements of the gerotor parts.