just got a 02 yz426/yes wont start


5 replies to this topic
  • jewellzy

Posted June 25, 2011 - 11:59 AM

#1

great condition,the guy had put a crank and rod.rings new gaskets ,he could not get it to start
i have checked for spark it has spark
now i have checked for the timeing,when i kick it to the comprestion till i cant move it ,the timeing mark is not there to be seen ,does that mean the timeing is off
any suggestions

  • Yamaryder29

Posted June 25, 2011 - 12:45 PM

#2

Your best bet would be to take the tank off, then turn it over to TDC, then open the valve cover and actually check the cam positions

  • jewellzy

Posted June 25, 2011 - 01:07 PM

#3

tdc would that be at where i cant turn it over any more,or if i pull the spark plug can i see where tdc is ,im kinda new at this

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  • grayracer513

Posted June 25, 2011 - 01:10 PM

#4

now i have checked for the timeing,when i kick it to the comprestion till i cant move it ,the timeing mark is not there to be seen ,does that mean the timeing is off (?)

No. It means you didn't get it to TDC yet. Compression starts when the intake valves close at about 120 or more degrees before TDC. Use a socket on the end of the crank, reach up and pull the compression release lever, and rotate it forward to TDC.

Assuming you have spark and the timing is correct, 90%+ of the reason a 426 will be harder than normal to start are carb related; things like plugged pilot jets and improper idle adjustment.

There is, however, the whole matter of proper technique:

Cold Start

Hot Start

  • SDBSKI

Posted June 25, 2011 - 01:11 PM

#5

I would check the valve clearance while your in there. Make sure there is a key installed for the flywheel. Who knows what the previous owner's mechanical abilities are. There are many ways to screw up these engines during assembly.

  • jewellzy

Posted June 25, 2011 - 01:32 PM

#6

well i twisted the gas 4 time and it started up





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