Yz450f build help

15 replies to this topic
  • erik86

Posted June 18, 2014 - 02:49 PM


I just rebuild my 03 yz450 and put everything back together and its like its locked up I can't kick start it..any suggestions

  • erik86

Posted June 18, 2014 - 02:55 PM


Forgot to mention that when I put in the timing chain it was tight with no play at all

  • erik86

Posted June 20, 2014 - 02:48 PM


I think it might have to do with the kick start the piston moves free but can't kick it..need help in a bad way

  • YZX

Posted June 20, 2014 - 03:12 PM


Hey, can you put it in gear and roll it?

  • erik86

Posted June 20, 2014 - 04:48 PM


It catches like it should
Should I try drift starting it?

  • YZX

Posted June 20, 2014 - 08:42 PM


Yeah, it's called bump starting. Try that

  • erik86

Posted June 21, 2014 - 02:34 AM


Will that free up the kick starter?

  • drtrcr400

Posted June 21, 2014 - 08:35 AM


Don't try bump starting it. If something is seized or your timing is off your likely to do much more damage. Obviously you did something wrong and it needs to be taken back apart. Seriously.

Edited by drtrcr400, June 21, 2014 - 08:36 AM.

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  • YZX

Posted June 21, 2014 - 09:19 AM


Hey Erik, your timing night be off too like drt said. Check that too.

  • erik86

Posted June 21, 2014 - 10:39 AM


OK so I drained the oil and took the screw plug of the side and turned the flywheel with a socket and everything turns fine the piston isn't seized and cams turn fine? Is there a wrong way to put the kick start shaft in? I replaced the whole thing shaft and gears

  • erik86

Posted June 21, 2014 - 10:44 AM


I got the timing right the first time I got TDC then lined up the indents on the cams

Edited by erik86, June 21, 2014 - 10:45 AM.

  • grayracer513

Posted June 23, 2014 - 07:22 AM


If the crank turns, the bike rolls when it's in gear and the clutch pulled in (even if it isn't easy), Then it's the kick starter.  Drain the oil and coolant and lay the bike on its left side.  Open it back up and see what's wrong.

  • erik86

Posted June 24, 2014 - 05:16 PM


OK I think I know what the problem is...I think the valves are hitting the top of the piston...so now how do I figure out what size shims to buy

  • Gutty

Posted June 24, 2014 - 07:26 PM


If that's the case, it's not shims you need. You have the timing out... be very careful or you'll just do damage.

  • grayracer513

Posted June 24, 2014 - 10:13 PM


I thought you said the crank turns.

  • erik86

Posted June 28, 2014 - 03:48 PM


I had thought it turned all the way but it stopped at the top

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