YZ timed ?

Is there an easy way to see if my 2001 wr426f has been timed to YZ specs? The bike had a lot of mods done to it by the previous owner and I am not sure what all has been done. I listed the ones that I know have been completed. Also can someone tell me the size of the stock gas tank?


Take the cam cover off, rotate to TDC and the punch marks on both cams should be at 9-12 & 3 oclock. The YZ timing will have 12 chain pins between the 12 oclock marks, WR timing will have 13. Try this web site, all free mods are explained very well. Site is for the WR250 but its all the same.


SP, also the tank is 3.17 gallons.

thanks for the help! It sounds pretty involved. Do I need to take the top of the engine off to look at the timing?

remove the tank and seat and y'll see the cam cover remove that and the two screw plugs in your left side engine cover to rotate the motor, refer to your manual for the position for TDC then count the pins as mentioned further up the page.

SP, You take the cam cover off. This involves two breather tubes and two allen head bolts. Once the tank is off its only 5 minutes to get the rest off. Keep in mind that on a 4 stroke it hits TDC every other turn of the crank. The punch marks on the cams will be at 9-12 & 3 oclock and the cam lobes will be pointing "out" on both cams. While your in there also check the valve clearances. The clearance is important and should be checked before problems start. Its a good idea to wrap the frames crossbar with Glad wrap etc. to keep dirt from falling into the open engine top. Have fun, easy process and a good way to get to know the bike.

thank you. I think I will give it a try and see what makes it tick.

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