Spark plug turning black.How do I fix this

Discussion in 'General Questions' started by plinko, May 23, 2010.

  1. plinko

    plinko Member

    I have a spark plug turning black.How do I fix this?I assume I am running lean.And this Is on my weed eater not my motored bike.Still be good to know how to fix this.

  2. wildemere

    wildemere Member

    Black is rich, you want tan or grey depending on the type of oil and oil mix. Most good weedeater carbs have a hi & lo mixture screw.

    If it cuts the grass leave it alone, if it four-strokes and won't rev up to speed then go ahead and lean it out.

    Playing with the 3 adjustments, idle, low and high can result in a non running machine if you are not familiar with them.

    My suggestion, take it to a lawn care shop and see if they will explain which screw is which then adjust accordingly.

    Otherwise google is your friend.

    A rich motor runs cool, it is preferable to a siezed lean (hot) one.
  3. plinko

    plinko Member

    A lil hard to start.But runs good.revs up also_On rare occasion It'll stop till I yank the cord.But all In all works good.Thank you windmere for clarifying this.I'll just run It the way It Is since It's running cool.
  4. GearNut

    GearNut Active Member

    You can always paint it tan! :p
    How fresh is the gas? When I run old gas through my weed eater the spark plug gets very unhappy and black. The engine seems to run fine though.
  5. plinko

    plinko Member

    About 2 weeks old.I use sta-bil In my gas to keep It fresh for months.Surprised cali has not arrested me for daring to use a 2 stroke weed eater.:grin5:
  6. GearNut

    GearNut Active Member

    My weed eater is a 2-stroke too. Fresh from the neighbor's trash can to my yard. It just needed a little TLC and now it screams! A Ryobi 32cc convertible shaft.
    My lawn mower used to be a 2-stroke 'till the CDI bit the dust which was not available anymore so I recycled the 'mower. All my leaf blowers are 2-stroke.
    Try using a new spark plug and see if it clears up to a dark brown. It could be as simple as that. For goodness sake, do not use a Champion spark plug. Go with NGK or Bosch if you can.