Sportster 533 with a ghost in the pump!

Discussion in 'Fettling Forum' started by Colin Geer, Apr 6, 2019.

  1. Colin Geer

    Colin Geer Subscriber

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    Got myself a Coleman 214 lantern and a 533 stove for £17!!!!! I wasn't expecting much and honestly just wanted the lamp as the 214 is not that common and I didn't have one. I have 2x 533s anyway and suspected it needed a new genny but having filled it it just worked! It needs a new pump washer but that's cheap. Thing is the pump handle pushes out when you've pressurised it so there must be a NRV leak but I've never repaired one in a Coleman before. Can it be freed with acetone maybe? It works well enough when you screw in the pump down but it needs fixing. Don't want a ball of flames!
     
  2. teckguy_58

    teckguy_58 United States Subscriber

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    If the pump handle is pushing out then the NRV will most likely need to be replaced.
    If you can remove the NRV and soak it in a 50/50 mix of acetone and ATF, automatic transmission fluid, for a few days that may be all it needs but don't forget to oil it up afterwards. The other method that some have used is to add the mix into the pump tube and let it sit.
    The Coleman NRV can be a real pain in the arse to remove. The NRV can be removed with a large screwdriver if you are careful, but there is a Coleman NRV tool which works great.

    Coleman has a pretty good design for their NRV system. If the NRV goes bad there is no liquid fuel poring out of the pump tube, but it does vent the air and fuel vapor from the top of the fuel tank/fount which can and will ignite. As can be seen the NRV vent tube always stays above the liquid fuel line.
    Snorkel.jpg

    Cheers,

    Norman
     
  3. Doc Mark

    Doc Mark Subscriber

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    @Colin Geer ,

    I've never had to remove a Coleman NRV, and have had total success with filling the pump tube with Acetone, and allowing it to soak for a few days. Plug the end with a cork, so you can shake it safely, every now and then. Then, in after a few days of that, empty the Acetone (back into the can from whence it came, actually), and rise out the tube with Coleman fuel. The assemble and try the NRV again. I'll get it'll be working a treat. If not, then repeat the above once more. For me, it's worked every single time!! Good luck, and God Bless!

    Doc
     
  4. Murph

    Murph United States Subscriber

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    @Colin Geer , the pump handle shouldn't come out in any event! if the NRV leaks, it should be venting out the center hole of the pump handle (if your thumb isn't over the vent!), or you screw down the pump handle and the leak becomes a non-problem.

    In any event, @Doc Mark hit it spot on for the stuck NRV, works a treat for that problem!

    Murph
     
  5. Colin Geer

    Colin Geer Subscriber

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    Thanks everyone. A soak in acetone is next on the agenda. And as you rightly said @Murph the pressure does come out of the centre hole, but when you've finished pumping and still have your finger on the end it pushes back at you like someone's working against you! Quite spooky.
     
  6. Murph

    Murph United States Subscriber

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    @Colin Geer , my Coleman 502 will do that too, especially when I tilt the fount for a maximum fill!

    With such a small space over the fuel for pressurization, I have the same thing happen, I learned to push the pump knob down, and then screw it in while holding it down!!!

    When the stove is that full of fuel, you learn to start it "The British Way", fill the centre of the burner with meths and preheat the genny, then crack open the valve, and off you go! I usually start it like that with almost no pressure in the fount, give it a pump or three and Bob's your uncle!

    Murph
     
  7. itchy

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    I've also had a few older Coleman's that had this symptom when I first tested them, but damn if it did not correct itself the next time I tried it a few days later. Others required the solvent approach. I have not needed to remove a check valve yet (knock on wood), but if and when I get that tool, I probably will just for grins.
     
  8. nagant

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    I would try Doc Marks approach also. Pump some acetone thru the pump tube nrv but leave some in the tube for a couple days.
     
  9. Majicwrench

    Majicwrench Subscriber

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    I've had many do this, and "fix" themselves after some use. Anything...carb cleaner etc down the tube will help.
    And....the NRV is not designed to be a perfect seal, so most will always push back against your thumb if you keep the hole plugged.
     
  10. Colin Geer

    Colin Geer Subscriber

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    I got the check valve out! It took some shifting but the slot is not damaged. It was completely funked up with black residue that came off with acetone until you could rattle the ball bearing easily. I put it back together and it still has the same problem but much less. I think I'll soak it again as there's probably a bit of gunk left in there.
     
  11. Majicwrench

    Majicwrench Subscriber

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    Like I said above,they are not designed to be a perfect seal and will ALWAYS push back a little bit, that is why you tighten the air stem.
     
  12. nagant

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    I had to check a few of my colemans, haven't lit them in 2 years:oops:. Lit 3 up and no problems once the pump cups loosened up. Don't know if it helps but i add about 2 ounces of seafoam to a gallon of fuel. I think it helps for long storage and maybe generator life:-k, cheap superstition if nothing else.
     
  13. phaedrus42

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    Before you scrap the NRV, a trick that has worked wonders for me is to gently tap the ball against the seat with a soft steel pin and small hammer. This reshapes the brass seat and effectively makes it seal again. Best to clean as well as possible beforehand.
     
  14. Colin Geer

    Colin Geer Subscriber

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    Good tip, Phil. I made it better just by cleaning it but it could probably do with another flush and I'll try the hammer trick.