00 426 timing

9 replies to this topic
  • s3706

Posted August 10, 2004 - 09:05 AM


If I set my timing using the yz timing specs the punch cog on the backside of the intake is slightly below the head but the exhaust punch cog is one link above the head. That is setting the top cogs 12 pins apart. Does this seem correct. If I change it to 13 pins apart on the top cog the intake is still slightly below the head and the exhaust changes to slightly above the head. I set it up for 13 pins apart and tried to fire it up but it backfires when I kick it. At one point it did fire up and run for about 30 seconds and that was the only time it started. Help Help!!

  • felony

Posted August 10, 2004 - 10:23 AM


i have mine exactly as you describe,my intake punch mark is down below the gasket surface and the exhaust is up a lil'bit,there are 12 pins between the 2 cams,when i first did mine it took forever to line the cams up but mine runs great so you should be fine :thumbsup:

  • s3706

Posted August 10, 2004 - 10:32 AM


I have it set right now at 13 pins apart. If I change it to 12 pins apart the exhaust cog is one link above the head surface. Should I change it to 12 pins.

  • felony

Posted August 10, 2004 - 12:04 PM


yes,12 pins is for yz timing while 13 is for the wr,yes the exhaust cam will be up a lil'bit :thumbsup:

  • Hamish

Posted August 10, 2004 - 06:34 PM


as the cam chain stretches the ex punch will be above the head and the inlet punch will be below the head.

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  • s3706

Posted August 11, 2004 - 04:27 AM


I changed the timing lastnight to 12 pins and made sure everything was set correctly. I tried to start it and it wants to backfire while kicking it. Any suggestions on what to check next.

  • jchantzWR400F

Posted August 11, 2004 - 04:59 AM


My guess would be that the cam chain came off of the crank while you were timing your bike. I would suggest that you start from scratch. Set your intake cam to manual spec. (how it appears in the manual) Then set your exhaust cam off of your intake cam 12 pins. It worked for me.

  • s3706

Posted August 11, 2004 - 06:50 AM


How should the cam lobes look when it is set correctly?

  • jchantzWR400F

Posted August 11, 2004 - 09:17 AM


They should be facing away from one another.

I want to say that the intake lobe should be slightly lower than the exhaust lobe at TDC. This is from memory though...not 100% sure.

  • 426_Texan

Posted August 11, 2004 - 07:18 PM


pics here near the bottom : http://www.thumperta...5/o/all/fpart/1

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