Fixed Orifice Positive Crankcase Ventilation (PCV)

Venting the crankcase of excessive pressure is good for minimizing oil leaks, but doing it intermittently in a D-Jet System messes with the MPS vacuum signal (per Ray Greenwood on ShopTalkForums.com - one of many posts on the topic here).  Ray recommends knocking out the spring loaded valve and replacing it with a 3-4mm fixed orifice.  I used standard 3.5 mm vacuum hose for the orifice.

Tools and Materials:
Drill
Instant epoxy
3.5mm vacuum hose

Procedure:
Step 1 - Remove breather from engine.  Remove cover plug from bottom of breather.  Unscrew knurled nut and remove valve.  Drill out disk riding on spring of valve.  Pull out spring and chunks of disk.



Step 2 -- Clean up valve and cut section of 3.5mm vacuum hose a bit longer than the valve body.

Step 3 -- Mix up epoxy and apply to ends of vacuum hose while hose is positioned centered in valve body.  Clean up excessive epoxy and let cure.

Step 4 -- Clean up breather, especially seal surface around bottom.  Reassemble and install with new cork seal.


Last updated:  8/14/07
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