WR400 rotor on a WR426-2002

6 replies to this topic
  • morpholik

Posted October 30, 2011 - 09:10 AM


Hi all,

I recently made a engine repair on my bike, new cranckshaft, connecting rod, piston, etc. Also, i used a WR400 base assy and rotor and changed the spark plug to a NGK IRIDIUM; it sparks but i have been unable to start the bike. Is there anything else i need to mod or something?
Hope you can help me:confused:


  • morpholik

Posted October 31, 2011 - 06:42 AM


Anyone? I'm getting really desperate...

  • morpholik

Posted November 02, 2011 - 05:52 AM


Maybe, because the WR's400 Crankshaft, connecting rod, etc are different from the 426's, the spark timing is not correct. Perhaps if i put one tooth forward or backward in the camshaft chain i'll get the correct explosion time, with the piston fully on the top.
What do you guys think?

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  • G_H

Posted November 02, 2011 - 10:36 AM


There is no difference in timing between 400 and 426 related to the crank. I've got a 426 crank with 400 flywheel in my 400 and it works perfectly.
Something else is wrong!

Don't mess with the camchain! It does not affect the timing of the ignition. It only changes the opening time of the valves.

  • morpholik

Posted November 02, 2011 - 03:25 PM


what do you think it is then? Did you had to do anything? I have stator plate and flywheel.

  • Birdy426

Posted November 02, 2011 - 09:49 PM


As long as all are installed correctly, it shouldn't matter if your parts are 400 or 426...
I would suggest going back and checking the cam timing, maybe pull the flywheel off and be sure the woodruff key hasn't sheared and allowed the flywheel to rotate. Check the carb as well. If you had the carb apart, you may have put the vacuum breaker plate in upside down (a pretty common mistake that makes the bike VERY difficult to start).

  • morpholik

Posted November 03, 2011 - 03:08 PM


Ok, stupid questions:
When aligning the flywheel whit the camshafts, do i gide myself by one of the H legs, or by the I in the flywheel?
When aligned, how many pins must i have betwen the 2 most distanced camshafts points?



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