yz timing, messed up


27 replies to this topic
  • Parx_400

Posted April 23, 2005 - 01:12 AM

#1

the last time i had my valves checked i had the dealer do it and do the exh cam mod to make it yz timed. i am currently putting hot cams in and to my amazment, the cams are both still in line with each other, but both seem retarded back 1 tooth. is this possible, would the bike run like this or am i missing somthing. i have never done the valves my self, this would be the first time.

  • Parx_400

Posted April 23, 2005 - 06:43 AM

#2

Help please, before i change it. Would the bike run with the intake rocked back one tooth?

  • Math

Posted April 23, 2005 - 02:00 PM

#3

So your stock cams are still in there? Is that what you are saying?. If so, count the number of chain links between the to top marks on the cam gears. 12= YZ timed. 13 = WR timed.


You can also set your engine at TDC and see which of the "E" or the "I" mark of the exhaust cam align with the head surface (have a look with your eyes at the level of the head surface) when the "I" mark of the intake cam is aligned to the surface. (And when I TDC, I mean TDC... not before or after, check at the bottom of the engine and align the marks properly as explained in your manual). If the "I" aligns, then you are YZ timed. If the E aligns, you are WRed.

As for the hotcams, I really think there is only one way you can install them as they are the same for the WR and YZ... refer to their instructions

HTH

  • Cedric

Posted April 23, 2005 - 06:22 PM

#4

Hmmm....
My bike came with 11 pins between the marks when I bought it. Is that wrong then? The bike runs very strong, I can't imagine its all wrong...

  • Bamster

Posted April 24, 2005 - 06:58 AM

#5

Can you take a picture of it and post it here ?

  • Math

Posted April 24, 2005 - 08:08 AM

#6

Something weird is going on... I vote for the picture. Maybe things are different for the 400s... :naughty:


Try do do a search in the WR4xx forum with YZ timing and 400 as search criterias and see what you can find.

Keep us posted.

  • Parx_400

Posted April 24, 2005 - 08:14 AM

#7

update. i was wrong. the intake was lined up ok

  • Cedric

Posted April 24, 2005 - 07:55 PM

#8

Ok guys,
Here it is. This was the way I bought the bike, is it true that it is corked one tooth the wrong way??? I just assumed that since it was off one tooth that it was set to YZ timing and left it alone.

  • jchantzWR400F

Posted April 25, 2005 - 06:43 AM

#9

Well, if those are stock cams and you've actually gotten the bike to start, I would be surprised. You actually have 11 pins between 12:00 timing marks.

Stock for the WR is 13. To YZ time, you move to 12.

I would set the bike to TDC. Keeping it in 5th gear while doing this will help keep the motor at TDC. Make sure while at TDC the intake cam marks line-up with the head (9:00 and 3:00). Now set the exhaust cam (12:00 mark) 12 pins off of the intake cam. By your pick, just rotate the exhaust cam 1 tooth counter clockwise.

Keep in mind that this advice is for stock cams only.

  • Math

Posted April 25, 2005 - 06:50 AM

#10

Ok guys,
Here it is. This was the way I bought the bike, is it true that it is corked one tooth the wrong way??? I just assumed that since it was off one tooth that it was set to YZ timing and left it alone.


If it was a 426, I would say with a lot of certainty that this bike is not timed properly.

We need the opinion of Frostbite on this one. He owns a 400 and knows for sure.

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • Cedric

Posted April 25, 2005 - 07:47 AM

#11

That's pretty wild guys, the bike runs and runs well too... I guess I should set them back to where they are supposed to be.

My Yamaha service manual shows the dots at 12 for both cams. Are the cams in the YZ and WR different, or does the WR come with the exhaust cam off the mark from the factory?

  • jchantzWR400F

Posted April 25, 2005 - 08:48 AM

#12

OK guys I've got a 99WR400. I can tell you with certainty that 11 pins b/w 12:00 timing marks is not correct with stock cams. Stock cams and stock wr timing puts you at 13 pins. Advancing the exhaust cam 1 tooth clockwise puts you at 12 pins b/w 12:00 marks.

My guess is that the cams are not stock WR cams. If they were, your bike would not be running properly.

If your manual shows 12 pins b/w 12:00 timing marks then you have a manual for the yz400 or yz 426...not the wr400 or wr426.

Hope this helps.

  • Cedric

Posted April 25, 2005 - 08:52 AM

#13

hey guys,
Have a look at this:

Motoman 393

Go to tech articles, how to YZ time and look at the last picture. He suggests turning the cam one tooth clockwise, the result would look exactly like mine does...

What is the right thing to do here, I'm getting confused now.

  • Math

Posted April 25, 2005 - 08:52 AM

#14

OK guys I've got a 99WR400. I can tell you with certainty that 11 pins b/w 12:00 timing marks is not correct with stock cams. Stock cams and stock wr timing puts you at 13 pins. Advancing the exhaust cam 1 tooth clockwise puts you at 12 pins b/w 12:00 marks.


So the 400 are the same as the 426 on this.

  • jchantzWR400F

Posted April 25, 2005 - 12:47 PM

#15

hey guys,
Have a look at this:

Motoman 393

Go to tech articles, how to YZ time and look at the last picture. He suggests turning the cam one tooth clockwise, the result would look exactly like mine does...

What is the right thing to do here, I'm getting confused now.



He suggests moving it forward a tooth because he is starting out with 13 pins b/w 12:00 timing marks.

I still say we're missing something here. When I originally tried this mod the chain slipped off of the crank and I went to 11 pins b/w 12:00 marks. It would not start. I then set the engine to TDC and aligned the intake cam as it was in the manual and set the exhaust cam 12 pins off of the intake. It fired up on the first kick.

Are you sure that the cams are currently stock? (Both intake and exhaust?)

  • Cedric

Posted April 25, 2005 - 01:12 PM

#16

Well since I bought the bike used I can't be 100% sure that the cams are original, but the bike was still on its original tires and had been used very little, so I'd be shocked if they weren't stock.

Motoman393's article states that the timing mark should be at 1 o'clock after the move. I think i'm going to advance the cam one tooth, so that I'm at 12 o'clock and the marks are where they should be (what should be YZ timing) and give it a try.

Everything else I've read suggests what you guys have been saying.

Thanks for your help on this...

  • Cedric

Posted May 01, 2005 - 03:48 PM

#17

Well I tried it, I advanced the exhaust cam one tooth, to get 12 pins b/w the marks, and although I only rode the bike very briefly, it seems like the power is softer. It used to have a bit more yank as the revs built up. Now I'm more confused than I was before I read this thread. Is it possible that the canadian bikes are different than the american's? I know there are other differences, such as no throttle stop, a different muffler, etc. I'd like to hear from more Canadians on this one...

  • dominator426

Posted May 01, 2005 - 10:54 PM

#18

My Canadian 2002 WR426 is like the others... 13 pins stock, and now at 12 for YZ timing (exhaust cam 1 tooth retarded/clockwise). Are you checking with your TDC timing mark at the | of the 'H|', with the timing chain slack taken up on the tensioner's side?
I wonder if your exhaust cam could have slipped forward as some 400 cams have been known to rotate in relation to its gear. Can you show us a view of the cam lobes as seen from the other side?

  • Cedric

Posted June 15, 2005 - 09:09 PM

#19

Can you show us a view of the cam lobes as seen from the other side?


Sorry for resurrecting this dead thread but...

I finally found the time to tackle this job. I decided to tear it down, and fix my leaking head gasket at the same time. I stripped it down, removed the cams, removed the head and blocked it down on a piece of glass with 400/600 wet (oiled) sandpaper. I took some photos of the cam lobes to show you guys what I am talking about. I ended up putting it back together with 11 pins b/w the timing marks on the cams, the way I had it before. It runs like a champ again, lots of hit for lofting the wheel or clearing jumps now. My head gasket leak seems to be a thing of the past too.

Here's how it looked:12 Pins B/W
12 Pins B/W Lobe Side

and how it looks now:
11 Pins B/W Marks
11 Pins B/W Marks Lobe Side

Do the lobes look like your guys' lobes look like with 13 vs. 12 pins? I don't even care much anymore, I know how the bike rides either way, and I know I like 11 pins better. Just thought I would add to this post for curiosity's sake.

  • Dirt_rebel

Posted June 15, 2005 - 10:54 PM

#20

i'm guessing dat ur cam chain is way overstreched..there is no way ur exhaust valve cud open wifout hitting the piston head unless ur chain is overstreched.. juz my opinion ..i cud be wrong :) ..btw i've installed a yz450f auto decomp cam on my wr400f n the manual says not to look at those punch marks :D ..looking at the cam lobes wud be more accurate..cheers :)




 
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