YZ450F cams going into WR450F (2007 into 2006)


12 replies to this topic
  • yamtoy655

Posted February 25, 2012 - 12:20 PM

#1

Hi

Can someone give me a straight and forward answer please?

How many pins between the 12 o'clock punch marks do i wanna see after the installation of YZ450F 2007 cams into my WR450F 2006 ???

I would really appraciate some help. I tried to read all the treads about that but its way to confusing.

FYI, I do have 14 pins showing right now on my stock WR450F cams.

Cheers

  • yamtoy655

Posted February 25, 2012 - 12:52 PM

#2

Please anyone, i really need some help....

  • yamtoy655

Posted February 25, 2012 - 08:44 PM

#3

All right, i went with 13 pins because 14 pins looked way to f%&*ed up. 13 pins look perfect. (punch mark level with the head). I started it and everything exploded.. Im just kidding, everything is fine with 13 pins.... But i would greatly appreciate if someone could tell me what they did.

Though,I do have massive decel popping now which i did not have before with the WR cams.

Cheers

  • 2grimjim

Posted February 25, 2012 - 09:24 PM

#4

Don't worry about counting pins. Just use the timing marks.

The pin counting trick was for the '98-'02 WR when you wanted to use YZ timing.

The YZ cams will require rejetting to get the best results. Popping on decel is from the idle mixture screw set too lean (not enough turns out).

  • cjard

Posted February 25, 2012 - 11:45 PM

#5

indeed, never count pins. Always line the marks up with the head, unless:

You want your WR cam on YZ timing in which case it's: align with the head and then move it one tooth forward so the mark is below the line of the head
or
You want your YZ cam on WR timing (in which case, align and then move one tooth backward)


Never read on anyone doing the second, but I did it on my YZ to make it less of an animal for the riding I was doing. Note i say "wr CAM" or yz "CAM" because it matters not what your *bike* is, it matters what the *cam* is

  • beezer

Posted February 26, 2012 - 05:43 AM

#6

When you put YZ cams in a WR the e-start doesn't work very well.

But it runs alot better.

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  • yamtoy655

Posted February 26, 2012 - 06:29 AM

#7

Awesome guys, i feel better now. I will set the carb and jetting though. I can't wait to go try it out.

{Beezer}, your right for the E-start. Its almost like the batterie is low on amps, but who cares....

  • 2grimjim

Posted February 26, 2012 - 09:38 AM

#8

indeed, never count pins. Always line the marks up with the head, unless:

You want your WR cam on YZ timing in which case it's: align with the head and then move it one tooth forward so the mark is below the line of the head
or
You want your YZ cam on WR timing (in which case, align and then move one tooth backward)


Like I said, this only applies to the '02 and earlier WR's.

If you try to move the timing on the '03 and later WR's you end up with no compression when you crank the engine. The '03 and later YZ's and WR's need to use the stock timing marks regardless of the type of cams you are using. This is to make sure the compression release functions correctly.

The '03+YZ cams will work fine in the WR (on '03 and later e-start bikes). There were issues with early Hot Cams for the YZ cams used in the WR not using the same decompression pin and too much compression keeping the e-start from working.

I don't know if Hot Cams has resolved this issue. I DO know for a fact that stock '03-'09 YZ cams will swap right into the '03+ WR with no problem using the stock timing marks, and the e-start will work just fine.

If I were to use YZ cams in my WR, I would either use the '03-'05 or the '06 cams. The lobe centers on the '07 YZ and '08-'09 YZ cams are too narrow and mike the power come on too hard. The lift and duration on ALL YZ450F cams from '03-'09 are the same. The only difference is the lobe centerline. WR cams from '03-'06 are the same lift and duration as the YZ, the only difference between the two is also the lobe centerline.

The stock YFZ (4 wheeler) exhaust cam CAN NOT be used in the WR. The YFZ compression release closes much earlier and the YFZ has lower static compression and a bigger battery also.

Edited by 2grimjim, February 26, 2012 - 09:40 AM.


  • yamtoy655

Posted February 26, 2012 - 05:46 PM

#9

[color="#011a4d"]2grimjim[/color]

That is an awesome answer. Thanks for the info and i bet you tons of people will us it.

To follow on on my WR, i adj. the air mixture screw and changed the main jet. Sounds like my decel popping as gone away.

My batterie WAS low on amps. Now fully charged, the bike starts as per normal.

  • beezer

Posted February 26, 2012 - 06:48 PM

#10

If you put YZ cams in a WR the e-start won't start the motor cold anymore.

And only half the time hot. Hot Cams are supposed to allow the motor to start easier with the button.

I used an 06 YZ exhaust cam with the stock intake cam on my 08 WR. My micrometer says the YZ cam has more lift.

But since the bike runs so good I'm leaving in what I have and not buying Hot Cams.

Plus I'm cheap.

  • 2grimjim

Posted February 27, 2012 - 08:50 AM

#11

If you put YZ cams in a WR the e-start won't start the motor cold anymore.

And only half the time hot. Hot Cams are supposed to allow the motor to start easier with the button.

I used an 06 YZ exhaust cam with the stock intake cam on my 08 WR. My micrometer says the YZ cam has more lift.

But since the bike runs so good I'm leaving in what I have and not buying Hot Cams.

Plus I'm cheap.


Is the starter not cranking the engine over? I've used the YZ ex-cam in the e-start WR with no problems. OEM cams that is. I know that the Hot Cams YZ spec ex-cam has caused issues. After a few years, I had a problem with my WR e-starter not always turning the engine over. Turns out that a new set of brushes and a fresh Yuasa battery fixed the problem.

2007 was the first year that the WR had cams that are completely unique to the bike and not based on the YZ cams. The intake was the biggest change. It has 1mm less lift and about 20 degrees less duration than the YZ cam. I have a set of stock '07 WR cams in my '03 WR450 with a stroker crank.

As far as measuring cam lift with a set of calipers or micrometers, that isn't really the best way to check. The base circle of the cam may be less than 180 on a cam with a lot of duration and you may actually be measuring part of the opening/closing ramp. The ideal way o measure cam lift is with a dail indicator with the cam on centers or v-blocks.

I just ran a bunch of Yamaha cams on a degree wheel but I haven't done the '07 WR cams yet. I'll get to them eventually, as well as some GYT cams and a set of '07 YZ cams.

Edited by 2grimjim, February 27, 2012 - 10:47 AM.


  • beezer

Posted February 27, 2012 - 01:03 PM

#12

The e-start gets the bike up on a compression stroke and just doesn't have enough snot to get it past it.

It isn't the battery cause I've tried different ones including the new Shorai.

The YZ cam fit without having to reshim so I assume the base circle is the same as the WR.

No WR450 I've ever owned would start good with the e-start cold so I just use the kickstarter.

  • 2grimjim

Posted February 27, 2012 - 03:15 PM

#13

The e-start gets the bike up on a compression stroke and just doesn't have enough snot to get it past it.


Have you ever replaced the brushes in your starter?

The YZ cam fit without having to reshim so I assume the base circle is the same as the WR.


The base circle is no different between the YZ and WR. What I was referring to is how measurements are taken when you try to determine valve lift (lobe height). A caliper or micrometer will only measure points on a circle that are exaxtly 180 degrees apart. Not all cams will the base circle extend the full 180 degrees. The longer the duration, the less likely that the base circle is at 180 degrees or greater. You can confirm this the next time you check your valves. Try checking the valve clearance with the nose of the cam lobe at a right angle (90 degrees) to the valve stem and recheck it at 180. Chances the clearance is going te be less or nonexistant. That's why it's so important to make sure the cam lobe is pointing as close to 180 degrees away from the bucket when you check valve clearance.

No WR450 I've ever owned would start good with the e-start cold so I just use the kickstarter.


The only time my WR is hard to e-start cold is when the outside temp is 40 degrees or less, but I can still get it to light with the e-start. I figured out a long time ago that hard e-starting (cold or hot) is caused by the idle mixture not be set correctly AND the idle speed being set too low.

Another problem is fuel quality, especially where I live. Anyplace where fuel containing 10% ethanol you are likely to find starting and jetting issues.

Edited by 2grimjim, February 27, 2012 - 03:16 PM.





 
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