How to: find TDC on KTM 450 XCF?

Discussion in 'Thumpers' started by Michelangelo, Jun 29, 2013.

  1. Michelangelo

    Michelangelo 2 wheel rider...anytime..

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    Just picked up a 2009 KTM XCF (dual cam of course) 450 and need to check valves. For a company which has amazing bikes and engineering, their service manuals are absolute garbage, worthless.

    I cannot find TDC, after 30 mins of turning the crank end and sticking a zip tie in the spark plug hole and looking for the mark on the cam chain gear. A few questions which may help you help me.


    1. To find TDC should I be rotating the wheel forward or the crankshaft bolt counterclock wise...correct?

    2. The 6mm bolt that is supposed to hold engine in TDC from the hole in the lower front of the engine: how far in is it supposed to thread in once I got it at TDC? (I can get it to thread all the way in until it keeps spinning but it doesn't stop or engage anything.)

    3. When I'm at TDC are the cam lobes on both cams supposed to be facing away from eachother or towards eachother or directly up?

    4. As mentioned my cam chain gear has just one indented mark on it. Whenever I get it to the top, where one would assume the engine should be close to TDC; the ziptie is never at it's highest and the cam lobes are neither facing directly at eachother or directly away from eachother!

    I know, I know I could be on the wrong stroke but I've turned that engine over a hundred times and I can't get anything to line up: If I get the cam chain gear mark on top, the zip tie isn't at it's peak or the lobes are facing every which way or vice versa. I'm stumped.

    I ended up just turning until I got the intake cam lobes facing straight up. Then check intake clearances. Then I turned until I got the exhaust cam lobes straight up, and checked the exhaust clearances.

    But I'd sure like to know how to get it to TDC so I can take the cams out and replace shims.
    #1
  2. RideFreak

    RideFreak Torque Junkie

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    #2
  3. Michelangelo

    Michelangelo 2 wheel rider...anytime..

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    Thanks for the link but it won't let me into KTM Talk.
    I got banned a year ago for criticizing the nazi like way the moderator ran things there. jerk.
    #3
  4. Foot dragger

    Foot dragger singletracker

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    Ive found top dead center using the bolt system several times,it took about 3 minutes. Your doing something wrong.
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  5. Michelangelo

    Michelangelo 2 wheel rider...anytime..

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    Yes, I KNOW. That's why I'm posting, asking for how to do it correctly.
    #5
  6. RideFreak

    RideFreak Torque Junkie

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    I know on the RFS the bolt gets removed, copper washer taken off then it's rethreaded in the hole, mine tightened up and didn't continue to spin. I was also able to shine a light up the hole and confirm the notch in the crankshaft before threading it in.

    Turn the motor over in the dir of rotation, just after the intake closes, monitor the piston location as it comes to the top (tiewrap or visual through the sparkplug hole) and once it reaches the top, you are at TDC.
    #6
  7. Michelangelo

    Michelangelo 2 wheel rider...anytime..

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    Maybe I'm putting it in the wrong hole? LOL

    So I took the bolt out of the right side of the engine. Then am trying to stick it in the hole that is in the front lower of the engine. Is that the correct sequence and location?
    #7
  8. FakeName

    FakeName Wile E Coyote SuperGenius

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    Don't bother:

    Adjust the intake when the exhaust is opening.
    Adjust the exhaust when the intake is closing.
    #8
  9. jar944

    jar944 Been here awhile

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    There are no marks on the cam gear or cam.

    When the flats of the cams are parallel lock the crank with the lock bolt...
    #9
  10. RideFreak

    RideFreak Torque Junkie

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    doesn't work that way on this motor, cams are removed and the shims are changed.

    on the RFS the TDC locating bolt resides, is stored in the same hole used to lock the crank, a washer is removed to allow the bolt to extend into the motor enough to pin the crank. Not sure if yours is the same though.
    #10
  11. Michelangelo

    Michelangelo 2 wheel rider...anytime..

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    Ok I tried your method of getting the slots on the camshaft lined up parrallel and then inserted locking bolt. I tried this two times, both times with the zip tie inserted into sparkplug hole so I can see that the piston was at or close-to TDC.

    Then I inserted locking bolt and not sure what next? I could get the bolt to insert and thread to the point where it would just rotate and rotate and not lock all the way into the hold. I think i ran out of thread on the bolt before anything. I even tried rotating the engine over to make sure it was locked AND...I could still rotate it over so i can only assume the bolt didn't lock it into TDC like it's supposed to.

    How far should the locking bolt be into the hold to assure me I have it at TDC and inserted correctly?
    #11
  12. larryboy

    larryboy Chopper Rider

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    Just to check? Should be able to get the lobes out of the way, check 'em, rotate until the other set is clear, then check those. No need to find TDC IMHO?
    #12
  13. Michelangelo

    Michelangelo 2 wheel rider...anytime..

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    Yeah I was able to check clearances by rotating lobes to the top. But I want to know the trick on locking it at TDC so I can remove cams and change shims.
    #13
  14. larryboy

    larryboy Chopper Rider

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    Why? I guess I don't get it? Getting close and taking out the tensioner won't work?
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  15. larryboy

    larryboy Chopper Rider

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  16. RideFreak

    RideFreak Torque Junkie

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    I don't think it has to be locked but since the option is there it's def nice to take that variable out of the mix.
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  17. Michelangelo

    Michelangelo 2 wheel rider...anytime..

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    Thanks for the article link. Great little write up, especially the pictures. Pictures, I can work with those!
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  18. jar944

    jar944 Been here awhile

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    You need a longer bolt in that case

    There are no alignment marks on the cams or cam chain. To swap shims you must pull the cams. To re install the cams the crank must be locked @ TDC and if you follow the service manual you need the special KTM tool to re-align the cams once reinstalled
    #18
  19. Michelangelo

    Michelangelo 2 wheel rider...anytime..

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    Ok so I finally got to TDC and got the bolt (took one from the handlebars clamp) to get in and lock the engine.

    My cam chain gear does in fact have one little indent mark but the odd thing (and thing that was causing me grief) is that it doesn't line up to the 12 o'clock position when the engine is at TDC. Is it possible that whoever put the engine back together after taking it apart, inserted that gear the wrong one, at least in regards to the indent mark? Not that it makes a difference in the overall scheme of getting it to TDC. But for someone who figured that mark was there for that purpose, it sure is a pain in my butt!

    So next time I'll know; don't look for the indent mark on the cam chain gear! I'll look for the lobes on each cam to be pointing away from each other, with the flat spots on the cams being parrallel to the ground.

    BTW, my clearances were on the far loose end of what the owner's manual says. Should I leave them loose as won't they get tighter as they wear anyways?
    #19
  20. larryboy

    larryboy Chopper Rider

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    Naw, you can stop it where you want...make your own marks with a paint pen and take out the tensioner, then remove the cams as needed. There is probably some cam overlap that tries to move the engine if you leave the tensioner in and that's why they have this lockout procedure that isn't needed if you pay attention...me personally, I'd only pop one cam at a time after removing the tensioner.


    Right, I never bother with TDC on any engine...watch your lobes and mark the cams yourself and just do it the same way next time. Like I was saying above, there is probably some cam overlap and that's why your center gear mark isn't at a true 12 o'clock.

    For a recreation bike I'd leave the clearance on the loose side, if you're racin' I'd tighten them up for a little more lift and check after every race weekend.
    #20