New Guy with Cam timing problems

6 replies to this topic
  • VE_SS_LS-2

Posted December 27, 2008 - 01:51 AM


Hi from Down Under,

I have a problem. I stripped my bike for a re-build, (04 YZ 450F) and ran out of time so I had a shop re assemble the engine. I got it started once back together, but it ran a little rough and within a few minutes of riding it the engine stopped and the rear wheel locked. I got it started again and it did it twice more. I just checked the cam timing and it is out. I found this site and thought that someone on here might be able to answer a question.

Question is, will the timing being out and the subsequent engine lockup have damaged anything? Looking for advice before throwing the engine through the front window of the bike shop.

Thanks in advance for your help

  • William1

Posted December 27, 2008 - 02:47 AM


Re-time the cams and see how she runs (if at all). If after re-timing it is a no go, then you know you have problems. While you have the cam cover off, confirm valve clearences are within spec, if one or more are way beg, you have a bent valve for sure.

  • 642MX

Posted December 27, 2008 - 03:39 PM


I'd take it back to the shop. The shop should stand behind the work they performed.

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  • BC3

Posted December 27, 2008 - 05:36 PM


[COLOR="Blue"]Yeah take it back to the guys that did the work...But to answer your question If the cam timing was installed to where it caused the engine to OVER HEAT .....and it STOPPED ....then yes it probably caused some damage (a seized piston comes to mind in that situation ) But yeah take it back and don't start taking it apart just take it like you rode it last....[/COLOR]

  • DeeCee

Posted December 27, 2008 - 06:16 PM


Take a look at your camshaft caps as well. If these have been over tightened (they have a very low torque setting) they can sieze and this may have been the cause of your lock up.

  • hillclimbguy

Posted December 27, 2008 - 11:44 PM


I agree, take it back to the shop. They should stand behind their work. Explain what happened. They should redo their work for no charge. Thier reputation depends on it.

  • VE_SS_LS-2

Posted December 28, 2008 - 02:14 AM


Thanks everyone for your answers, Could it have put a valve into the top of the piston?

I spent $1600 on the engine and want it running like it was before the rebuild.

I will take it back to the shop now without touching it and have them do a full strip and rebuild at their cost.

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