Table of Contents
This is an old revision of the document!
REF: Engine Mechanicals - Sub-05I
79-85 Breather Vent Mod - Adding a Secondary Vent Hose at 6:00 Position
See also in the Sportsterpedia:
- Breather Venting / Relocation (especially the sub documents at the top of the page)
- Installing the extra hose:
- You do not need to remove the cam cover to do this. The 6:00 o'clock position has a 1/8“ NPT Allen head plug.
(same plug as on the corners of the rocker covers)
- Simply remove the plug and replace it with an 1/8” NPT hose fitting and hose.
Moving the 10:00 Hose to the Bottom to Use an Aftermarket Air Cleaner
- Moving the line is relatively easy.
- The 10:00 o'clock position has 1/2“ NPT threads in the cover.
You can pull the plug, install a fitting and lower hose, remove the upper hose and install a 1/2” NPT plug in it's place. - Both upper and lower vent holes access the internal valve equally and function the same way.
- Considerations.
- However, plugging the 1/2“ NPT outlet and using the smaller 1/8” NPT outlet may reduce crankcase vacuum.
You also may get a little more oil drips simply because it is at the bottom (gravity). 3)
Good for oil scavenging but not as good for ring seal.
1)
photo by 83XLX of the XLFORUM http://xlforum.net/forums/showthread.php?t=1332902&page=3
2)
photo by 83XLX of the XLFORUM http://xlforum.net/forums/showthread.php?t=307208
3)
IronMick of the XLFORUM http://xlforum.net/forums/showthread.php?t=1757228