XB breather systems/XB breather re-routes/XB breather mods are some of the most heavily discussed and misunderstood topics on this forum and have been for ages. be prepared for possible info flood along with the occasional horribly incorrect recommendations that accompany same. here's the basics you need to know along with part numbers to resolve your problem. NOTE: this is from experience....memory...dealer TSB's...and schematics. NO copy and paste!
1-XB's use sportster-based architecture for much of the motor/trans/primary assembly.
2-the crankcase cavity is what i call "shrink-wrapped" around a single crank-pin assembly. this means the air volume within the crankcase is ever-changing and will work efficiently ONLY if generated air is allowed to escape and NOT be sucked back into the cavity.....hence the one-way airflow design of each rocker cover PCV valve.
3-a properly done and simplistic breather modification adds a few HP and allows the motor to ingest pure atmosphere and gasoline as opposed to air/gasoline/contaminated crankcase fumes. keep it simple. google "buell XB breather modificiation" then click images. the ones with 3/8th inch ID oil lines connecting to a T fitting then a single identical line going to the rear of the bike with simple $10 open filter assembly at end is what i use and recommend. the "catch can/drain/shut-off valve" gizmos all bull**** and should be avoided. completely unnecessary and needless complexity.
4-replacement part number list as follows and infinite quantity still in dealer system:
17606-00YA - Grommet, Viton, Black $2.95 each (need 2)
17607-00Y - PCV Valve, $6.90 each (need 2)
NOTE: engine will need to be lowered(rotated) to replace the above items. simple tutorials available on this site.
5-lastly...the IAT sensor is a critical component of the EFI system and somewhat fragile in its construction. if yours appears compromised or cracked where the wiring harness socket attaches it should be replaced. check it closely.
factory part # is P0138.K list price $18.49 infinite # still in system.
and if the above isn't enough info for you here's a link to everything you could possibly ever want to know about XB breather systems....mods...problems....working configurations....do's and don'ts. attached pic is example of simple mod and the basic style of plumbing i've been using for years. works well and bomb-proof.
http://www.badweatherbikers.com/buel...tml?1034394025
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