2005 CRF250R Rebuild

Discussion in 'Some Assembly Required' started by Raindog18, Sep 18, 2018.

  1. Raindog18

    Raindog18 Rock it till the wheels fall off

    Joined:
    Apr 20, 2015
    Oddometer:
    45
    Location:
    Montana
    So... after rebuilding my KX65 pitbike I had the confidence I could rebuild a 4 stroke, and as I turns out I can’t at least not yet. I bought a 2005 CRF250R off Craigslist for $550 and put a new crank, bearings, spark plug and gaskets in the bike (copper shavings were in the oil). But it just won’t start after getting it back together. It has back fired a few times and sounded like it wants to start but won’t. What can I check besides the timing and valves? Am I just not kicking it hard enough lol maybe I should stick to little 2 strokes. Thank you very much for any and all help!
    #1
  2. pro69ss

    pro69ss Adventurer

    Joined:
    Aug 28, 2018
    Oddometer:
    89
    Location:
    St Petersburg
    Did it run before rebuild ?
    #2
  3. nickguzzi

    nickguzzi Long timer

    Joined:
    Feb 17, 2010
    Oddometer:
    5,960
    Location:
    below the sea
    Any ie engine needs fuel, ignition and compression. Start there.
    #3
  4. Raindog18

    Raindog18 Rock it till the wheels fall off

    Joined:
    Apr 20, 2015
    Oddometer:
    45
    Location:
    Montana
    Nope I bought it and the oil had large chunks of copper in it, so I just took it apart right away.

    Well it would have spark if the bike fired for that split second, fuel also and it does take a good kick to get the motor to turn over. I’ve rechecked the valves and timing everything seems to be good. Maybe a wire is undone that I missed?
    #4
  5. cedric

    cedric Been here awhile

    Joined:
    Nov 7, 2006
    Oddometer:
    257
    Location:
    Calgary
    Are the valve clearances within the specs? Those bikes were notorious for valve issues.
    #5
  6. neil w

    neil w Been here awhile

    Joined:
    Jan 13, 2013
    Oddometer:
    212
    Check the timing isn't 180 degrees out
    #6
    jake28 and Bultaco206 like this.
  7. Raindog18

    Raindog18 Rock it till the wheels fall off

    Joined:
    Apr 20, 2015
    Oddometer:
    45
    Location:
    Montana
    Yep the valves are in spec. For the timing it’s have the cam lobs facing back and line up the timing marks in the case correct?

    Also today I put new gas and sea foam in. It was a little closer but still didn’t. Maybe try rebuilding/cleaning the carb?
    #7