Venting the XR1200 Engine
The XR1200 has three primary points that are routed as breathers/vent tubes. 
  • The first of these are the two vent ports in the rocker arm covers.  In a stock XR1200 these are the main way that internal engine air pressure is vented to the outside world.  On the XR1200 these two vents are connected through a "T" in the airbox, to route pressurized engine air/gases into the throttle body to be burned by the engine.
  • The second is the crankcase breather on the right side of the engine at the base of the rear cylinder.  This port is connected by a vent tube to the oil tank and is intended to equalize pressure between the oil tank and engine to support the flow of oil to the oil pump from the oil tank.
  • The third is the the oil tank pressure release valve in the top of the oil tank.  (This air pressure relief valve was added in 2010.  It is not found on 2008 and 2009 XR1200's, unless they have had a warranty, or other, replacement of the oil tank with the later version.

The following links give a look at the engine crankcase breather air flow, and an easy mod to let the top of the engine breathe a little more easily.

The below links  show what I have done in terms of externally routing the breathers and/or installing oil catch cans.



The following link has a look at a simple test to examine the amount of air that travels through the breather ports.


Will write something later...

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