• 5 Speed Oil Pump on 4 Speed Models (Conversion for 86-90 Evo engines)
• Images of 98-06 XL Oil Pump - 26402-98 & 26402-91A (old design)
• Images of 07-later XL Oil Pump - 26402-91A (new design)
• Images of 07-later Buell Oil Pump - 26357-02B
• Notable Separator Plate Design Change / Flaw Between the BUELL (03-06) & (07 & up) Style Oil Pumps
• Comparing the (98) & (07) Style Oil Pumps

Note: Be sure to check the REFERENCE section for additional information related to Oiling, Lubrication and Mods.

1986-1990 Models - XL P/N = 26204-86

1991-1997 Models - XL P/N = 26204-91
- has bottom cover casting P/N 26487-90

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
- has bottom cover casting P/N 26487-98

2000-2006 Models - XL P/N = 26204-91A
- P/N change appears to be related to a fitting (to oil filter) change
- has bottom cover casting P/N 26487-98

2007-later Models - XL P/N = 26204-91A (new design)
- is a 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 design) but different fittings
- will bolt up but you need to change the fittings over to XL style
- has bottom cover casting P/N 26213-07

See these XLForum threads:
http://xlforum.net/forums/showthread.php?t=135265
http://xlforum.net/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-later version:

¹⁾

• 2007 XB engines got a new up-dated oil pump which will retro fit to older EVO Sportster Engines, BLAST engines and older XB Engines … ²⁾
• The -07 XB oil pump is part number 26357-02b. The 07 part number seen on the housing is simply just for the lower housing. ³⁾
• The part number for a 2006 is 26357-02A. ⁴⁾

• The -07 Sportster pump changed at the same time and got the same improvements and the only reason the part number is different from the Buell pump is that the fittings are different. And what's more, just a brief look at some parts books shows that the part number for all Sportster pumps from 2000 to thru 2007 + is the same (26204-91A). So they changed the pump in 2007 as Buell did. However, it doesn't appear that they changed the part number. So with the 07-up XL style oil pump, even though the pump’s part number didn’t change from the 2000 model year, the gerotor part numbers did.
• Both the Sportster 2007 Oil Pump (26204-91A) and Buell 2007 Oil Pump (26357-02B) have gerotors with the following same part numbers:
  • Feed — 26503-07 GEROTOR SET
  • Return - 26502-07 GEROTOR SET
• So, it does appear that the Sportster got the same oil pump improvements. Why they changed the Buell pump part number in '07, and yet didn't change the Sportster pump part number at the same time, I have no idea. Just to confuse us I guess. ⁵⁾
• The Sportster pump #26204-91A and the Buell pump # 26357-02B are the same ⁶⁾
• The only difference in the pumps are the fittings that come installed on the pump ⁷⁾ which can be removed and replaced with the fittings that you need for your XL.

• 1991-later Oil Pump Drive Gear Upgrade 26391-06

Check your oil pump drive gear if you've gotten your gearcase cover off anyway to hopefully prevent gear failure before it happens.

• This is a common failure in Sportsters, even when nothing got into the pump and locked it up first. ⁸⁾

Oil Pump and Drive Gear Damage 9)