KTM 300EXC cylinder walls ok? (pics)

Discussion in '2 smokers' started by ubercooper, Aug 6, 2012.

  1. ubercooper

    ubercooper Adventurer

    Joined:
    Nov 2, 2010
    Oddometer:
    16
    Im doing a top end on my 00 300 and noticed the cylinder walls looked worn... Is this normal?

    There is no actual scoring, but Im wondering if it will be ok with a good cleaning or I should it sent off to be re-sleeved/plated ?

    Thanks in advance

    [​IMG]

    [​IMG]
    #1
  2. 2trally

    2trally Adventurer

    Joined:
    Aug 2, 2012
    Oddometer:
    62
    Location:
    Arizona
    Its hard to tell from a picture, but it might just need to be honed.
    #2
  3. ubercooper

    ubercooper Adventurer

    Joined:
    Nov 2, 2010
    Oddometer:
    16
    Here are a few better pics of the 2 spots I am worried about.. I will try honing it tomorrow and see what it looks like... I have also heard of people deglazing the cylinder but that might be more trouble than its worth

    [​IMG]

    [​IMG]
    #3
  4. Twin-shocker

    Twin-shocker Long timer

    Joined:
    Jan 28, 2012
    Oddometer:
    1,673
    I would guess that either the piston is totally worn out, or more likely dirt has got into the motor somehow.

    You wont be able to hone Nikasil using conventional stones, but you can use them to remove material form a seized piston though. If the piston is worn/damaged then it would a good idea to get the cylinder re-plated, and if it looks like damage has been caused by dirt also check bottom end carefully.
    #4
  5. ubercooper

    ubercooper Adventurer

    Joined:
    Nov 2, 2010
    Oddometer:
    16
    Thanks guys.. Ended up going with a replate from PowersealUSA
    #5
  6. Shocktower

    Shocktower Long timer

    Joined:
    Jul 27, 2009
    Oddometer:
    9,535
    Location:
    Oregon City Orygun
    I have heard in England they use Nail polish to repair those













    :hide I am J/K Twin shocker :D
    #6
  7. Foot dragger

    Foot dragger singletracker

    Joined:
    Dec 27, 2006
    Oddometer:
    13,732
    Location:
    chico,just below rag dump(nor-cal)
    DIAMOND HONE! Thats what the shops use,1 very quick pass is all it gets,if the tolerances are there its good to go.
    That does look like a good amount of dirt ran through it.
    #7
  8. Twin-shocker

    Twin-shocker Long timer

    Joined:
    Jan 28, 2012
    Oddometer:
    1,673
    Where can I buy a diamond hone? Wok on Nikasil motors quite a lot and it would be a useful thing to have.
    #8
  9. PSchrauber

    PSchrauber Been here awhile

    Joined:
    Jan 3, 2011
    Oddometer:
    979
    Location:
    Summer: Kemiƶ, Finland; Winter: North Germany
    #9
  10. Twin-shocker

    Twin-shocker Long timer

    Joined:
    Jan 28, 2012
    Oddometer:
    1,673
    Thanks..............looks way too costly for occasional use though? I get the feeling that something like a flex hone might be more suitable?
    #10
  11. Pmason

    Pmason Been here awhile

    Joined:
    Nov 8, 2009
    Oddometer:
    145
    Location:
    Maine
    From my research at ktmtalk, I decided NOT to use a hone on my cylinder. Most recommend using dawn soap and a green pad to remove the glazing. If you have any scoring or scuffing (something you can catch a nail on), a replate is the best option.
    #11
  12. Ever Onward

    Ever Onward Older,Wiser, Smarter

    Joined:
    May 1, 2011
    Oddometer:
    1,276
    Location:
    The open road towards the sun !
    Good idea, because if you hone the plateing to thin on the high spots, you run the risk of flakeing.

    You can even start with the red pad before the green to clean up quicker.
    #12