Lister Junior

Discussion in 'Help Wanted' started by steve wiltshire, May 3, 2020.

  1. steve wiltshire

    steve wiltshire New Member

    Hi Folks. Any one able to help me source a carb for my Lister Junior. Mine is badly over fuelling and appears to have an internal problem as it was running fine and no settings have been changed. Thanks
     
  2. petternut

    petternut Administrator

    There is no guarantee that one you bought would be in good order, nor would it be cheap. If it were mine I'd take it off and apart in order to understand, and hopefully fix, the problem. It might be as simple as the weir tube or return pipe being partially blocked.
     
  3. steve wiltshire

    steve wiltshire New Member

    Yes i have checked all that and assume there could be some corrosion perforation between the fuel chamber and venturi which is very difficult to check because of the way the carb is cast. Thanks for your reply
     
  4. petternut

    petternut Administrator

    May I also suggest cleaning the needle seat? Remove the needle and insert a piece of 1/4" dowel sharpened to a pencil like point. Twiddle round in the seat and keep refreshing the tapered end until the dowel comes out clean.
     
  5. campingstoveman

    campingstoveman Active Member

    Going back to basics why do you think its over fueling and to query your point that no settings have changed will be incorrect as you adjust the carburetor everytime you start and run it, can you explain how you start the engine and what position you set the choke and what do you do with the needle to start and then get the engine running.
    If you can tell Roland and I all of the above we may have an answer to your problem.

    Campingstoveman
     
  6. steve wiltshire

    steve wiltshire New Member

    I will try the dowel trick. I have tried pipe cleaner but perhaps not harsh enough to work. Starting procedure from cold has been the same since i have had the engine. Strangler 3/4 closed, petrol on, hand pump fuel to chamber, open petrol regulator 3/4 then fire up. Open strangler and turn down regulator for low, smooth running.. No problem for months until it stopped running after 10 minutes and i noticed fuel running out the air intake. Will only run for seconds after letting fuel evaporate and same thing happens again. Took carb off to check over only to find a pool of fuel run out of the inlet. after leaving for a few days the fuel in the chamber was lower than usual with no external leaks so am thinking leak into the venturi. Have been running the engine regularly over the last several months with no problems. Engine had been stored outside and was corroded and seized externally when i got it at that time but looks a treat now. Really appreciating your replies and thoughts. Steve
     
  7. steve wiltshire

    steve wiltshire New Member

    Will try it. Thanks
     
  8. campingstoveman

    campingstoveman Active Member

    The Lister manual for the A & B types says that on light load to run the engine with the choke more closed than open and only to open when making the engine work hard, one of my A's weeps out of the choke and I stop this by running the way the manual suggests, still turn the regulator down until it settles to steady running.

    Campingstoveman
     
  9. steve wiltshire

    steve wiltshire New Member

    Will try anything at the moment! Have even reread the manual myself but like i said this is something out of the norm as the engine has been brilliant up till now with the same procedures every time. Will update the forum when i get time to tinker again as i still work at the moment
     
  10. campingstoveman

    campingstoveman Active Member

    The only other thing I would suggest is what Roland has told you already, clean the jet seat and the return pipe to the tank and maybe try a thinner fibre washer under the return pipe in the carburetor to lower the level.

    Campingstoveman
     
  11. TangyeDan

    TangyeDan Active Member

    If there is fuel running out of the air intake it may be that you have a sticky inlet valve stem. I wouldn't be surprised at the fuel in the chamber dropping over a few days. It is not well sealed and petrol does evaporate! The other old adage also springs to mind... "Most Carb problems are electrical". Running for 10 minutes is classic of a short circuit in a magneto coil when it gets warm.

    Good luck!

    Dan
     
  12. campingstoveman

    campingstoveman Active Member

    Dan,
    Well done, I wondered when somebody would spot that, carry on ;)
    Campingstoveman
     
  13. steve wiltshire

    steve wiltshire New Member

    Obstructed silencer! Previous owner thought good idea to ram chicken wire in exhaust and with me running it over time it has coked up. Phew. Still got some hair left. Just. Had already thought of exhaust and had put a bag over to see if flowing but obviously not enough. One of my first suspicions which i tried last! Thanks to all for your thoughts. Steve
     
    TangyeDan likes this.
  14. steve wiltshire

    steve wiltshire New Member

    Obstructed exhaust. See below. Thanks
     
  15. campingstoveman

    campingstoveman Active Member

    Dont you mean "look above"
     
  16. steve wiltshire

    steve wiltshire New Member

    Yep. Was not sure where that would land. My first forum! Glad it doesn't show. Cheers
     
  17. campingstoveman

    campingstoveman Active Member

    I've been on this Forum for seventeen years, so Ive just found out, and I still get things wrong so I shouldn't worry.

    Campingstoveman.
     

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