How to clean your gas cap

Discussion in 'How To Guides' started by Fire-medic, Sep 27, 2018.

Help Support VMAX Motorcycle Forum by donating:

Tags:
  1. Sep 27, 2018 #1

    Fire-medic

    Fire-medic

    Fire-medic

    Well-Known Member

    Joined:
    Mar 25, 2011
    Messages:
    8,662
    Likes Received:
    13
    Location:
    Miami Florida
    I have a bike that had a stuck-on gas cap. No spray penetrating oils would allow the cap to release.

    I had to cut off the gas cap/tank neck to release the cap. A new one (gas cap) lists for $160+ at partzilla.com, and probably considerably more at your friendly dealership.

    If you do have to cut your filler neck, be very-careful you don't cut the cap! From the lip of the gas cap neck to the bottom of the gas cap installed, it's one inch. You have two choices, either cut more-than that distance on the neck, or be very careful and use a cut-off tool to just penetrate the gas neck tubing around the tubing. I used a cut-off tool/side grinder and a thin cut-off blade to make that cut where the gas cap stuck-down beneath it, being very careful to only cut through the metal, and not into the gas cap beneath it. I used a piece of masking tape to make a guideline to follow when making the cut.

    If you don't trust your hand, then just measure about 1/2" off the surface of the gas tank, mark the line to cut-to with masking tape, and cut there, you will be below the gas cap.

    You will probably have to re-position the tank several times to make a clean cut around the filler neck. Take your time.

    No amount of soaking freed the cap, no spray, it had to be cut-the filler neck. You can use a piece of rubber gas rated tubing and a pair of hose clamps to make things functional again. Paint the bare metal edges before assembly.

    Here is the cleaning:

    I removed the screws from the cap underside. I suggest you do the disassembly in a box, so you don't lose the small springs under the gas cap locking tabs. One tried to run-away from me, and I've done this disassembly before.

    The gas cap die-cast cup which holds the tabs will come-off when the two machine screws are removed. Be careful that the tabs stay in-place, because those pesky springs are underneath the die-cast cup and the tabs. The springs are what push the tabs into place so you can fasten the gas cap.

    Now that you have removed the die-cast cup, you should be staring at the two moving tabs, underneath of-which are the springs, waiting to jump off the cap and roll-to god-knows where.

    Carefully remove one tab at a time, and be ready to grab the spring underneath. Put the spring into something like a pill bottle or a jar with a top on it. Now, remove the second tab, and the second spring.

    There is a flat plate underneath the die-cast cup with two holes that is a plate to separate the die-cast cup from the gas cap. Remove it.

    For cleaning, I used a glass bead blaster, a bench grinder wire wheel, and a piece of sandpaper. Whatever you use, clean everything to remove any corrosion or smegma from all the parts. To clean the springs, I used a piece of baling wire to thread each spring onto, and then introduced it to the wire wheel. Lightly, as the springs are light gauge. The baling wire acts as an 'axle' to keep the spring confined, hold the wire on either side with the spring in the middle, and clean it.

    Everything is shiny, yes? Clean?

    Place the flat plate with the two holes in it onto the gas cap. You can thinly-coat the tabs with grease, and place each with its spring onto the notches in the gas cap that isn't disassembled. When the key is turned, those notches rotate 90 degrees, and they retract the tabs to allow the gas cap to be released.

    I did not coat each tab entirely with grease. I coated the sides of the tabs with grease, and placed them with the springs onto the gas cap notches that move when you turn the key. I had already greased the inside of the gas cap die-cast cup which holds the tabs. Now place the die-cast cup over the tabs. You may need to push-in on the tabs as-if you were turning the key, to more-easily seat the die-cast cup.

    Be sure that you install the die-cast cup with the sticking-out notch on it on the same side as the outside of the gas cap 'arrow' which is pointing to 12 o'clock when you re-install your gas cap after a fill-up.

    I replaced the phillips screws with allen screws, you could use stainless steel ones. They're about 15 mm long. Snug them down, they don't need to be tight.

    Insert your key and try your refurbished lock, it should work 'like buttah.'
     

    Attached Files:

  2. Sep 27, 2018 #2

    D-Max2012

    D-Max2012

    D-Max2012

    Well-Known Member

    Joined:
    Oct 25, 2012
    Messages:
    1,185
    Likes Received:
    0
    Location:
    NJ
    Wow.. That's extreme..
    Anytime something with rubber is locked in place against a metal surface, I'd try the penetrating oil 1st.. If that didn't work, my next step would be to heat up the metal neck with a heat gun.

    Glad you got it off.
    I suspect the tank was being tossed out anyway?
     
  3. Sep 27, 2018 #3

    Fire-medic

    Fire-medic

    Fire-medic

    Well-Known Member

    Joined:
    Mar 25, 2011
    Messages:
    8,662
    Likes Received:
    13
    Location:
    Miami Florida
    The gas cap was corroded to the point that in my opinion, no amount of heat and liquid penetrant would have gotten it to release. Only removing the assembly would allow the tabs to release; the corrosion locked them immobile. Once the parts were thoroughly-cleaned and greased, it works fine.
     
  4. Sep 27, 2018 #4

    D-Max2012

    D-Max2012

    D-Max2012

    Well-Known Member

    Joined:
    Oct 25, 2012
    Messages:
    1,185
    Likes Received:
    0
    Location:
    NJ
    Yes, I guess if the tank was corroded that bad to lock the cap in place,, it would not be worth saving.

    Whatever tank you replace it with, take the time to coat it.. I wish I had done mine sooner.. I would not have wasted over 1500 hours of carbs, tank, pump, and performance issues.
     
  5. Sep 28, 2018 #5

    gentsvmax

    gentsvmax

    gentsvmax

    Well-Known Member

    Joined:
    May 24, 2012
    Messages:
    331
    Likes Received:
    1
    Location:
    denver
    Didn't he re-use that neck/tank with hose and clamps?
    I think so...hope so.
     
  6. Sep 28, 2018 #6

    Traumahawk

    Traumahawk

    Traumahawk

    Well-Known Member

    Joined:
    Dec 12, 2011
    Messages:
    7,607
    Likes Received:
    0
    Location:
    Lawton, OK
    Thank you for posting. I might need to referb a couple of caps BEFORE they get that bad.
     

Share This Page

arrow_white