Gas cap breather installation

Discussion in 'General Questions' started by ccpomea, Nov 7, 2010.

  1. ccpomea

    ccpomea Member

    My engine kept cutting out, realised that my gas cap was air tight which was blocking fuel flow.

    Found brief reference in an old post on the forum about installing a breather from a dirtbike so I ordered one from eBay. Thought some picture's might help people out. I have a small lathe which makes it easier but this could be done with basic hand tools.

    Drilled center of gas cap - pilot hole first.

    01 pilot.JPG

    This is the hose coupler I bought from local hardware store, I just picked one I thought would work best.

    03 coupler.JPG

    Then drilled out the gas tank hole to just a bit smaller than the diameter of the coupler.

    02 drill.JPG

    And shortened the coupler, also turning it down to match the hole in gas cap.

    04 chucked.JPG

    05 turned.JPG

    Roughed up both surfaces with a bit of sandpaper and epoxied them together.

    06 epoxied.JPG

    And after a few hour's attached the eBay breather (I ended up removing the tip of the coupler because it was a bit longer than neccessary).

    07 installed.JPG

  2. RedBaronX

    RedBaronX Member

    looks a lot better than my venting job
  3. motorpsycho

    motorpsycho Active Member

    wow, seems like an AWEFUL lot of work just to vent the gas cap.
    one of my gas caps isn't even a gas cap at all. It's a chrome push in oil fill cap for a car valve cover($4.99).
    I vented it by just drilling a small hole in the center of the cap, and the I epoxied this little $1.49 pewter charm over the hole. The back side of the skull is all open and the eyes are open, so the cap is vented, but you can't see the hole in it.
    It took me literally 5 minutes to make it, it looks cool, and is functional.
    yeah I know you're thinking "what about water or rain entering the hole and getting into the gas?"
    #1, i don't ride my bikes in the rain. #2, I don't wash my bikes with a hose.

    Last edited: Nov 7, 2010
  4. ccpomea

    ccpomea Member

    Not a lot of work at all, took me longer to write the thread.
  5. motorpsycho

    motorpsycho Active Member

    but you say "after a few hour's attached the eBay breather"
    so to me it sounds like it took you a few hours to do this.
  6. ccpomea

    ccpomea Member

    The epoxy I mentioned right above that had to cure....
  7. motorpsycho

    motorpsycho Active Member

    ahh, that makes more sense now.
  8. wheelbender6

    wheelbender6 Well-Known Member

    Cool. i'm interestged in venting my cap that way. I hate the way fuel seeps out onto the tank when it is close to full.
  9. ccpomea

    ccpomea Member

    I had the opposite problem, my tank was airtight - engine would cut out from lack of fuel.

    You might be fine just replacing the o-ring.
  10. hurricane

    hurricane Member

    :idea:that why he vented it :idea:
  11. ccpomea

    ccpomea Member

    My response was to wheel bender saying he has gas leaking on top of his tank... I guess I should have quoted it, but I didnt think anyone would think I was replying to the OP - as thats me.
  12. hurricane

    hurricane Member

    oh snap !! you are right , ma bad :whistling:
  13. I took a Hand drill and a drill bit the size of a pencil led and drilled a hole in the center of the cap....Took me 2 minutes if that and I have no problems with gas coming out or water getting in....The hole doesnt have to be any bigger than the amount of fuel being used by the engine....The size of jet is smaller than a pencil lead....
  14. RedBaronX

    RedBaronX Member

    yeah, there is no need for anything fancy if the bike is stored indoors and is never ridden in the rain.

    I get some gas that sloshes out. On my "eventually" list is getting a new cap so I can do a vent job more like the OP
  15. curtisfox

    curtisfox Member

    How about doing like the lawn mower cap with a cardboard like washer with a offset hole to one side inside the cap? That should defer the splashing..........Curt
  16. RedBaronX

    RedBaronX Member

    it might help, but what I know happens with mine is that gas sloshes up into the cap, gets trapped amongst the components of plastic, metal, rubber, and then bubbles out from there. It's not directly splashing out like if you were to run with a glass of water.

    I know that is what is happening because the gas gets caught in the cap and inhibits the breathing-- not as bad as not having it vented at all. I have to drill another hole to make sure the gas that is getting caught up there will drain back out.

    Oh, and I am using a Whizzer gas tank, not a stock Chinese tank, so the inside of the cap is more elaborate.