fouling plugs question

Discussion in 'Engine' started by Racer51, Mar 21, 2013.

  1. Racer51

    Racer51 New Member

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    hi guys this question is aimed at an 01 YZ250 I'm looking at. The dude said the bike fouls out a plug every couple of 1hour rides. Fouling a plug basicly means it's running rich right?
    All it has is a full length powercore 2 pipe and uni filter and the owner before him jetted high and sold it to him. So I can just swap out for a hotter plug change the pre mix oil to synthetic Dominator 32:1 premium gas from what ever he was using and run it.
    Or should I do the giant PITA job of taking the carb off and checking the jets when I probably get the bike this weekend? PS running a wot run for a plug chop would be a serious pain cause there would be no front wheel on the ground so just plug chop the old one when I get new ones?
  2. Wifesblaster

    Wifesblaster Built not bought

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    Buy my bike! I posted it earlier in the miss section :)
  3. Racer51

    Racer51 New Member

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    trading pretty much even up for my blaster the dude lives 5 miles away it dosent get much better than that lol yes alots stock but thats how I want a 250 to be for now YZ 250
  4. Blaaster

    Blaaster Moderator Staff Member Technician Forum Supporter

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    The first thing I would do is leak test is to see if he is trying to cover up an air leak by jetting rich.

    In my vocabulary there is no such thing as just swap out a plug, change the oil and premix ratio and hope it runs right.

    Put in the recommended heat range plug, check what jets are in there, correct if needed, adjust the float and idle as to manufacturers specs.

    Now do a plug chop, by the way there is a thing that is called a brake on the back wheel.

    You do not have to be at full speed to plug chop, apply the brake so that the motor is under load, and pulling well.

    Question?

    What oil is it using at this time.
  5. Wifesblaster

    Wifesblaster Built not bought

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    I can plug chop my 250. Lean forward and let it eat!
  6. Racer51

    Racer51 New Member

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    what I ment by swap out plug for the stock/recommended plug.
    lol yea I tend to forget when all my instincts kick in doing a 60MPH wheelie funny how that happens will do though.
    OK I thought for the most part you had to put it through 1-5-6 gears and shut it off and put the extra plug in it to get home. thanks will do when i get everything figured out
  7. Blaaster

    Blaaster Moderator Staff Member Technician Forum Supporter

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    You have to make the motor pull hard through the gears, and you can get quite a good reading in 4th gear as long as you give it long enough to develop the smoke ring.
  8. Racer51

    Racer51 New Member

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    I called him again and asked him what the jetting in the carb was yesterday and he just now texted me 50Pilot and 178main and thats whats it comes with stock. So the owner before him dident jet high so there is still the problem of koffing black stuff on the plugs.

    Did a bit of research and found a lot of yz125s and 250's of all years seam to do this when running with less than hospitable temps below 45'(shrug) thanks wifey and blaaster I'm supposed to meet the guy 2mro so we'll see. If i do i'll plug chop when weather gets good 50+ and so i can check the jetting I can get 2 or 3 original plugs cause all he has it the old one. ad obviously post pics if I get my desktop working.

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