Starting 450 cam mod/found something strange?

13 replies to this topic
  • jimn

Posted November 09, 2004 - 01:14 PM


Help!Broke down bike(02 yz426) to start cam mod and something doesn't look right with cam timing to begin with It has never been apart(I bought it new)and as far as I can recall,last time I checked valve clearance it did'nt look like this.At first I thought flywheel mark was different(steahly complete which is basically a stock with weight on)but that does not make sense with marks being off(according to manual)I am going to try to include pics so maybe some of you can help me out with an explanation.THANKS!!Jim PS I hope I didn't screw up link to pics(1st time) Posted Image Posted Image Posted Image

  • jimn

Posted November 09, 2004 - 01:30 PM


Well,let me try this again. Posted Image

  • jespertheil

Posted November 09, 2004 - 01:33 PM


Mine is a bit off too but don´t worry. After what i heard it comes because of a little chain slack. If you follow the manuel you can´t install the chain wrong. I know that when you turn the engine to TD center your small dots on the cams wont be in perfect line. Belive me you will notice if they are a whole toth or more of timing. Just make sure that wings on the intake and exhaust cams are pointing away from each other, then you are on the right trrack to asemple it right.

Good luck and remember you can´t ask to much in here.. Better safe than sorry.. :cry:

  • jimn

Posted November 09, 2004 - 01:35 PM


Thanks,Did the picture even come through?I can only see a red x.Jim :cry:

  • Satch0922

Posted November 09, 2004 - 03:29 PM


e-mail me the pics and I would be glad to look at it. Check your pm's

  • jimn

Posted November 09, 2004 - 04:19 PM


Satch,I sent you the pictures.Let me know what you think!Thanks!Jim

  • Satch0922

Posted November 09, 2004 - 06:06 PM


Check your e-mail. I sent pics of what the cams should look like properly timed. I may be wrong but it just looks like maybe you need to recheck yyour timing mark on the flywheel. Let us know!

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  • jimn

Posted November 09, 2004 - 07:27 PM


Satch,I sent you an e-mail,Iam thinking that the exhaust cam mark looks good and the timing mark looks good that the problem might be the intake cam(as it is the side with tensioner)being off one tooth.At this point I am not sure.Jim :cry:

  • Satch0922

Posted November 10, 2004 - 06:27 AM


if your timing marks are lined up then you are correct....the intake cam is off.

  • jimn

Posted November 10, 2004 - 06:28 AM


Okay, I have checked timing mark(even did dowel in spark plug hole)and it appears to be accurate,the exhaust cam timing mark looks good at that point,but not the intake.Does anyone have a picture of top end pre 450 cam?Or maybe know the # of pins between stock top marks.I too am having trouble believeing it is off a tooth,but you never know.THANKS!!,jim

  • jimn

Posted November 10, 2004 - 06:34 AM


Satch,Since it seems I am off one tooth,should I rotate intake to fix first,then check clearances,then proceed with 450 cam install?Or just do it all at once?Jim

  • Satch0922

Posted November 10, 2004 - 07:44 AM


Your going to have to correct the timing of the intake cam anyway and to ensure you have a proper measurement of the valve clearances I would go ahead and time it correctly. Check your clearances on the intake cam and reshim if needed. That way you eliminate that variable.

Then install the 450 exhaust cam per the PDF instructions.

  • jimn

Posted November 10, 2004 - 07:58 AM


Satch,That's kind of what I figured.If I need to reshim (intake)can I do it at the same time I reshim for 450 cam?I have to mail order shims around here.Thanks for all the help!Jim PS if anyone does have a picture pre 450 cam I'd still like to see it.(can't hurt at this point)

  • Satch0922

Posted November 10, 2004 - 11:30 AM


go ahead and time the intake, measure it , determine what (if any) new shims you need. Then go ahead and install the 450 cam and meaure it. That way you can order shims at the same time.

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