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Crankcase breather

Discussion in 'The Garage' started by dlabkeeg, May 29, 2010.

  1. 5twins

    5twins XS650 Guru Top Contributor

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    Today, it's an emissions or pollution thing. Years ago, all engines vented to atmosphere, even cars.
     
  2. gggGary

    gggGary Stop that! XS650.com Supporter Top Contributor

    Road tube!
     
    Team Junk likes this.
  3. gggGary

    gggGary Stop that! XS650.com Supporter Top Contributor

    Like the factory did it? Well yeah!
    That's my goto, a big part of why I stick with stock air boxes in front of stock carbs.
    Standards 76-79
    20200519_172516.jpg
    Specials 80 up
    80 up specials PCV.jpg
    One I made for madness. a 79 750; used a later breather box and plumbing then made some copper risers and flanges to penetrate and seal against the uni filters.
    Madness PCV.jpg
    The set up always goes down then back up to the airbox. I think the theory is at lower speeds any oil escaping the crankcase sits in the plumbing, then at higher RPM increased air flow pulls it through the carbs to be burned in the combustion chambers.
    Not all cleaned up for viewing! :laugh2: :redface: several thousand miles since installed.Much of that running hard.

    Skull told you what would happen if you let gary's messy bench near a nice bike...
     
  4. Bushyeyed1

    Bushyeyed1 Cafe Racer XS650.com Supporter Top Contributor

    I used a catch can made for a go cart when I removed my airbox. 9E0F13BA-173B-4A6A-8B1E-A4A52238D63C.jpeg 81AE3A2C-DA7A-4ED2-89B9-03408DC80283.jpeg
     
    gggGary likes this.
  5. Tiesco

    Tiesco XS650 Addict

    Where'd you find that?
     
    gggGary likes this.
  6. Machine

    Machine Race the wind Top Contributor

    I found mine at O'Reillys Auto parts. Tho they couldn't find it in their system.. I spotted it on their hooks lol
    Its just a Ford etc.. style old brake booster check valve
     
    gggGary likes this.
  7. Tiesco

    Tiesco XS650 Addict

    I tried to find one at advanced auto a while ago but I didn't find anything
     
    gggGary likes this.
  8. 5twins

    5twins XS650 Guru Top Contributor

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  9. DirtyErnie

    DirtyErnie Renaissance Hick

    Power brake check valve into some short black tube, clear vinyl running down the back of the engine, under the carbs. Curves up to the frame spine, topped with a cheap push-in breather filter between the foam pods. It keeps everything in the area well oiled, although it seems like less of a mess since I replaced the O'Rilley's 20w50 with Castrol GTX.
     
  10. Heres my solution to the problem and even has a vacume gage to let u see wat ur makeing . Comes with all mounting hard wear and even the hose to attach it with and clamps for 25 usd. Shiped right to ur front door has a filter built in and everything a man could want for the price it blew my skirt up anyway
     

    Attached Files:

    Bushyeyed1 likes this.
  11. TwinLewi

    TwinLewi XS650 Addict

    Where might I ask you purchased those filters? Great set up!
     
  12. Its called a oil tank and at wish .com if u look around a bit u can snag the 1 like i got with internal filter,hose & clamps and even a vaccum gage just for good measure in a veriety of colors for lik 20 bucks
     
    TwinLewi likes this.
  13. bosco659

    bosco659 XS650 Addict XS650.com Supporter

    Interested in your comment that pod filters will cause carb tuning issues. Can you please elaborate? Thanks.
     
    gggGary likes this.
  14. 5twins

    5twins XS650 Guru Top Contributor

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    Pleated K&N type pod filters are the troublesome ones. The pleats disrupt the air flow, make it turbulent, and that messes with the slide lift on these CV carbs. Best pods to use on these are the straight foam UNI pods.
     
  15. bosco659

    bosco659 XS650 Addict XS650.com Supporter

    Thx. I’m running 32mm PWK carbs. At the filter end they are 54 mm or close to 2-1/8”. Had a look at Uni’s website an it looks like the diameter jumps from 2” to 2-1/4”. Does the urethane flange have enough “give” to stretch the 2” over my 2-1/8” carbs?
     
  16. 5twins

    5twins XS650 Guru Top Contributor

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    The PWK are a regular slide carb so you could use the K&N type filter on them. But yes, if going with a UNI, the 2 1/4" will tighten down just fine to 2 1/8". The 2" version would be a stretch and very tight. I don't recommend it.
     
  17. bosco659

    bosco659 XS650 Addict XS650.com Supporter

    Gre
    great thx
     

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