04 yz450 won't start. What am I missing?


4 replies to this topic
  • bikridr69

Posted April 17, 2016 - 07:39 PM

#1

my buddy's 04 yz450 won't start. Put a new head and piston and rings on it. It started n ran but had a ticking/knock, sounded like from the top end. Checked the timing and it might have been a tooth off. Changed that and put it back together. Now it won't start at all, only tried kicking it.

  • defilmcrew

Posted April 17, 2016 - 11:18 PM

#2

I would check timing again first. Also is there compression after reassembly? If not or low check for a bent valve (cup stuck partially down)

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  • bikridr69

Posted April 18, 2016 - 03:00 AM

#3

I would check timing again first. Also is there compression after reassembly? If not or low check for a bent valve (cup stuck partially down)


It has compression (I didn't measure it with a tester) but feels the same as before when kicking. I will check the timing again and check for bent valves after work.

Edited by bikridr69, April 18, 2016 - 03:03 AM.


  • toten

Posted April 18, 2016 - 06:13 AM

#4

The easiest way to find a bent valve is excessive clearance. 



  • grayracer513

Posted April 18, 2016 - 06:28 AM

#5

If it has normal compression, why would you suspect bent valves?







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