450 Cam mod (on WR426) how many pins??


60 replies to this topic
  • NuckingFuts

Posted December 19, 2005 - 10:30 PM

#1

I have an 02' WR426 with a 450 exhaust cam already installed but cant tell if its YZ timed or not. Ive read that stock WR timing has 13 pins between the 12 o'clock punch marks. But Ive also read some guys had 14 pins.

My question is what timing does my bike have if there is 13 pins between punch marks right now?

  • NuckingFuts

Posted December 19, 2005 - 11:17 PM

#2

Where can I find the instruction pdf file on the 450 cam mod on the 426's? It used to be a sticky in the YZ forum but its gone. I searched but its a dead link now.

  • horsappl

Posted December 19, 2005 - 11:33 PM

#3

I downloaded the document in .jpg format a while back. If you give me your email address I can forward these to you. Email me at vhorn@hotmail.com

  • blue_beast_wins

Posted December 19, 2005 - 11:33 PM

#4

Question is, do you know if its a WR or YZ cam, they are different and cant be changed from what they are, if you do the auto decomp doesnt work properly.

  • NuckingFuts

Posted December 19, 2005 - 11:40 PM

#5

Question is, do you know if its a WR or YZ cam, they are different and cant be changed from what they are, if you do the auto decomp doesnt work properly.


Its an 03 450 cam.

horsappl, I emailed you.
:applause:

  • Indy_WR450

Posted December 20, 2005 - 03:05 AM

#6

I believe you have a YZ450 exhaust cam with 13 pins. :applause:

  • jbrooks26

Posted December 20, 2005 - 03:14 AM

#7

need to recheck my facts. I will repost when I am sure. Sorry.

Josh

  • jbrooks26

Posted December 20, 2005 - 03:33 AM

#8

Ok, I find several posts that say 14 pins and there are even a few pictures with 14 pins. I believe that if you look at an 03 YZF it is 14 pins also. Hope this helps.

Josh

  • NuckingFuts

Posted December 20, 2005 - 08:49 AM

#9

Ok, I find several posts that say 14 pins and there are even a few pictures with 14 pins. I believe that if you look at an 03 YZF it is 14 pins also. Hope this helps.

Josh


I also saw the pics with 14 pins, I even saw instructions that have a pic with 14 pins between but state NOT to go by pin count but rather the orientation of the cam lobes in relation to each other.

Ive also seen 'yz timing' instructions for 2 stock WR cams(no 450 cam involved) in which the WR ex. cam was changed from 13 pins (stock) to 12 pins (yz timed). This confuses me.
Wouldnt the pin count for yz timing be the same regardless of whether or not the 450 cam is installed? :applause:

  • Indy_WR450

Posted December 20, 2005 - 10:30 AM

#10

I think the confusion on pre 2003 wr & yz timing comes from the old days of 13 vs 12 pins using the same cam between stamped points on the cam sprockets. The 2003 and newer bikes require a factory cam swap so you go to standard pin postiions and the cam lobes will vary in position. Therefore YZ and WR cam timing should look the same as far as the punch marks and pins between punch marks. It is my understanding that 13 pins is the distance for both cams between punch marks on the cam. :bonk: Please enlighten me if I am wrong. :applause:

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  • NuckingFuts

Posted December 20, 2005 - 10:49 AM

#11

According to the dealer work order, its a YZ450 cam(part#5TA-12180-00-00) from an 03' with yz timing, throttle stop removed, grey wire clipped, decomp hole plugged.

So,
Q: With YZ450 cam in, how many pins represents wr timing and how many pins represents yz timing?

Here's a pic of my timing as seen from both sides. what do you think?

Left side

Right side

  • Indy_WR450

Posted December 20, 2005 - 11:46 AM

#12

I think the confusion on pre 2003 wr & yz timing comes from the old days of 13 vs 12 pins using the same cam between stamped points on the cam sprockets. The 2003 and newer bikes require a factory cam swap so you go to standard pin postiions and the cam lobes will vary in position. Therefore YZ and WR cam timing should look the same as far as the punch marks and pins between punch marks. It is my understanding that 13 pins is the distance for both cams between punch marks on the cam. :cry: Please enlighten me if I am wrong. :bonk:


As I said above 13 pins is what I see and your Dealer is right :applause:

  • jbrooks26

Posted December 20, 2005 - 01:15 PM

#13

According to the dealer work order, its a YZ450 cam(part#5TA-12180-00-00) from an 03' with yz timing, throttle stop removed, grey wire clipped, decomp hole plugged.

So,
Q: With YZ450 cam in, how many pins represents wr timing and how many pins represents yz timing?

Here's a pic of my timing as seen from both sides. what do you think?

Left side

Right side


On the 03 and newer, there is no such thing as YZ timing and WR timing without a Cam Swap. The # of pins will be the same with WR and YZ timing, it is the Indexing of the cam lobes to the timing marks on the gear that is different, and if you go moving the cam to try and achieve the different timing then your auto decomp won't work properly and you will risk bending valves due to the decompression opening early or late. In the pictures it looks to me like your exhaust cam lobe is too high, suggesting to me that you need to move it one tooth counter clockwise looking from the sprocket side. However, I am no professional. I would suggest taking those pics to your local dealer and checking with the mechanics. If they won't answer that question for you I would find another dealer. Hope this helps, and please let us know what comes out of this.

Josh

  • NuckingFuts

Posted December 20, 2005 - 01:21 PM

#14

As I said above 13 pins is what I see and your Dealer is right :applause:


So Indy, you think its already yz timed? What are you comments about the exhaust cam being slightly different than the intake cam? It doesnt seem to be a large enough difference to be 1 tooth off.

Burned suggested I check to ensure my timing was correct since I cant seem to get rid of this bog at 1/2-full throttle by means of jetting.
:bonk:

  • RD73

Posted December 20, 2005 - 01:23 PM

#15

Looks like your exhaust cam needs to be rotated one tooth counter-clockwise (if you are looking at the bike from the "left" side photo).

Don't pay any attention to the timing marks on the cam. The marks won't and should not line up. Look closely at the cam lobes. That is the reason it looks off to me.

  • Indy_WR450

Posted December 20, 2005 - 01:56 PM

#16

rotating it one tooth further counter clockwise looks like a bad idea to me. :applause: The timing in the picture looks right but is not be taken exactly at TDC. :bonk:

  • NuckingFuts

Posted December 20, 2005 - 02:02 PM

#17

rotating it one tooth further counter clockwise looks like a bad idea to me. :bonk: The timing in the picture looks right but is not taken exactly at TDC. :cry:


my "I" in HI is lined up with the case markings. :cry:
Id agree with Indy, it just doesnt look like large enough difference to be an entire tooth off. Hard to say unless I did a comparison. :applause:

  • NuckingFuts

Posted December 20, 2005 - 02:19 PM

#18

I found this thread where a few guys were confirming that 14 teeth is correct. Not sure what to go with here

http://www.thumperta...345#post1364345

  • NuckingFuts

Posted December 20, 2005 - 02:50 PM

#19

Correct me if Im wrong here:

If you have the WR450 cam, then lining up the punch marks (at TDC) would give you WR timing.

If you have the YZ450 cam, then lining up the punch marks (at TDC) would give you YZ timing.

In otherwords, you shouldn't have to advance the cam 1 tooth to get the YZ timing with a YZ450 cam. Punch marks will line up like THIS
(Or in my case there seems to be only one punch mark to line up)

  • Indy_WR450

Posted December 20, 2005 - 04:10 PM

#20

You got it figured out right! :applause:




 
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