WR426 Valve check...? Need a little help.

Well after this last ride I figured I better check my valves.

I've never checked my valves. I've owned the bike for 1 year and put on over 2000 trail miles, any way I'm finding out alot about this bike.

It appears to still be WR timed. It has been running great with ZERO mechanical issues!

I'm having a hard time checking the valves clearances.

I'm not sure I'm at top dead center.

If the bike is WR timed shouldn't the Intake cam dots be level with the cylinder head and the exhaust dots be advanced one tooth?

So if this is the case then I should check the clearances with the Intake cam dot's level with the cylinder head.

I did not do this.

I checked the clearances with the Exhaust cam dots level with the cylinder head.

See pic:

47671586-L.jpg

What should I do???

  • Should I set the "H" in the center of the flywheel window or the "I"? There appears to be the word HI in the window.
    47603026-M.jpg
  • Since the bike appears to be WR timed should I check the clearances with the Intake cam dots level with the cylinder head?

Your help is much appreciated.

Just turn the crank till the cam lobe is straight up from the lifter bucket. Do it visually for intake and exhaust. Watch out on the exhaust cam that the auto decompres is not lifting the valve. Forget the dots!

For starters, you are WR timed. Look at the 12:00 timing marks on each cam and then count the number of pins between. You are at 13. Needs to be 12 for YZ timing. As for being at TDC, you need to make sure the "I" in "HI" is in the center of the hole. To help ease this process, put it into 5th gear and turn it over untilt he engine is at TDC. Having the bike in 5th will help keep it at TDC.

Forget about how the timing marks line up with the head.

I thought YZ timeing for this model was 13 pins? :applause:

For starters, you are WR timed. Look at the 12:00 timing marks on each cam and then count the number of pins between. You are at 13. Needs to be 12 for YZ timing.

If this is the case then my timing is not correct.

My manual states that the "E" dot on the exhaust cam and the "I" dot on the intake cam should line up with the top of the cylinder head. They DO NOT!

47671586-L.jpg

I'll check the valve clearances again tonight after some more tinkering.

Looks like one of my intake valves is WAY out of spec!

If this is the case then my timing is not correct.

My manual states that the "E" dot on the exhaust cam and the "I" dot on the intake cam should line up with the top of the cylinder head. They DO NOT!

47671586-L.jpg

I'll check the valve clearances again tonight after some more tinkering.

Looks like one of my intake valves is WAY out of spec!

I understand where you're coming from. I also struggled with this when I first tried to switch to YZ timing. I was looking at the picture in the manual and it didn't look like the E and I marks were lining up like they should (according to the pic in the manual) with the head.

I wouldn't sweat it. It's not going to look exactly like the pic in the manual.

I understand where you're coming from. I also struggled with this when I first tried to switch to YZ timing. I was looking at the picture in the manual and it didn't look like the E and I marks were lining up like they should (according to the pic in the manual) with the head.

I wouldn't sweat it. It's not going to look exactly like the pic in the manual.

Yeah,... I finally realized that everything is OK. The pic in the manual is for reference only. I was still WR timed and two of my intake valves were way out of spec. I reshimmed the intake valves and went to YZ timing.

Thanks for all the help! :applause:

wait wait wait wait.04wr450,i can change the cam timing to yz spec?pls someone begood to me,would love more free power.thanx

wait wait wait wait.04wr450,i can change the cam timing to yz spec?pls someone begood to me,would love more free power.thanx

only if you swap out the wr exhaust cam for the yz exhaust cam and it ain't free.

this free mod was only good for 98-02 models.

the autodecomp on your 04 wont allow you a simple twist of the cam.. gotta upgrade to the yz cam and then you will be good.. :applause:

YZ cam just puts power higher in the rev range. Not gives you more power.

Which one do you want? Get hotcams if you want more power.

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