2009 WR450F Timing

2 replies to this topic
  • watkins

Posted January 21, 2012 - 04:22 PM


Hi All,

Just finished up my first valve clearance check of my new 2009 wr450. Couple of Q's... everything was in-spec except the middle intake clearance. The manual didnt list a different spec for it so I just used the one listed for just the intake valves. and I had to go one size down on the shim.... anyways long story short I didnt mark the chain & sprocket and then struggled to get the timing back right.... Got it as close as I could and put it back together.. started up with the choke on but ran pretty rough with the choke off...

So I pulled it apart again and realized why I was struggling so much to get the sprocket marks aligned right.. I aligned the sight with the "H" mark and not the TDC mark.

Once I got it aligned right (or as close as I could with my "crooked" eyes) I was able to fight with the intake camshaft and get it back right again.

Started right up with the choke on & Idles fine with the choke off.. doesnt start too well warmed up with the choke off.. but then again it never did. Always took a 5-6 turn overs or the hot start pulled in.. any surefire method of making sure everything is ship shape? In the future any tricks to getting the camshaft & chain aligned right? I just kept taking the intake cam off.. fiddling with it and putting it back in.Then I would get it perfect only to realize somehow I pulled to hard on the chain and got the crank off of TDC...

If things arent perfect on the timing are we looking at any potential damage to the motor?

Thanks.. I've been a 2-stroker my hole life.. all this stuff is new to me.

Excuse and typo's or wierdness.. have a 4month old going crazy on my lap as I try to type.

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  • 2grimjim

Posted January 21, 2012 - 07:59 PM


It depends on which direction the timing is off. If the Intake is advanced too far, or the exhaust is retarded too far, the piston could contact the valves and bend a valve. If this happens, the damage would be the instant the engine turned over and it most likely wouldn't start or run.

  • MANIAC998

Posted January 23, 2012 - 04:24 AM


I'm pretty sure that if the timing is off by one tooth in either direction, the bike will still run without causing any engine damage. But like Grim said, if your off more than that you can cause complete engine failure. I'm willing to bet that you've got it right, and your starting issues are probably more related to jetting, etc.. Do you have it re-jetted and de-restricted? Maniac


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