yz450f 08 can slip

3 replies to this topic
  • dougie-yzf

Posted March 05, 2014 - 02:15 PM


Asked to moto mechanics in town yesterday about the tdc mark they both said the T on its side is this right? my intake cam has slipped in the bearing therefore when I line the marks up my intake lobe is at 12 0'clock dont think thats right and my exhaust is on 7 0'clock where its suppose to be any way. So last night I lined it up with the T and ignored the marks set my lobes at int at 2 and exhaust at 7 started up 1min tink! Don't know what happen but something broke don't know did I do something wrong I've had this bike apart 8 times since I bought I'm starting to give up.

  • grayracer513

Posted March 05, 2014 - 04:32 PM


There is no "T on its side" anywhere.  On the flywheel, there are 3 radial lines near TDC.  The first two from left to right are connected with a crossbar to resemble an "H".  Those are for ignition strobe checks.  The remaining line is TDC.  If in doubt, remove the spark plug and check for Top Dead Center with a long narrow screwdriver blade.


The cams are then set up as shown below:


If the cam chain has ANY tight spots in it, replace it and buy a new tensioner, before you wipe out $1000 worth of cylinder head, or worse.

Attached Thumbnails

  • marks.png

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  • dougie-yzf

Posted March 05, 2014 - 06:38 PM


I thought it was the mark after the "H" because I used the screwdriver trick last time and it started first kick. Can you do the timing by just going off the lobes on the can because decompression side looks like it seized and spun out.
When I line it up like you have shown
On your pic my lobes dont look right
The decompression side sits at 12 O'Clock and intake sits on 7 o'clock
Thanks for the info

  • grayracer513

Posted March 06, 2014 - 07:55 AM


In that case, the cams need to be replaced, and there is probably some damage to be repaired in the cam bores on the head.

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