WR450 timed to YZ requires new cam or not?


10 replies to this topic
  • Robert_Brazil

Posted December 15, 2004 - 06:03 PM

#1

Cab someone tell me whether timing my WR450F to YZ timing requires anoher camshaft, or not (like I did with my 426, just advance the cam one tooth) Thanks for the reply!

  • ddialogue

Posted December 15, 2004 - 06:16 PM

#2

Cab someone tell me whether timing my WR450F to YZ timing requires anoher camshaft, or not (like I did with my 426, just advance the cam one tooth) Thanks for the reply!


You have to install the YZ cam in order to get the YZ timing. It's required because if you advance the WR cam one tooth, the auto-decomp circuit will no longer function.

Correct me if I'm wrong, guys. :cry:

  • BrandonW

Posted December 15, 2004 - 06:27 PM

#3

you got it right Dave! :cry:

You CAN turn the '03 and newer WR450 cam over to YZ settings, but you will lose the decompression feature. To keep that (the decompression ability of the '03 and newer cam) , you have to get the YZ cam which is weighted in the right spot for that cam alignment.

For $100, get the YZ cam and be one happy man!

:cry:

  • Robert_Brazil

Posted December 15, 2004 - 06:37 PM

#4

Thank you for the prompt reply, we´re referring here to the exhaust cam, right? Would that be part number 5TA-12180-00-00 that I would need. Some one on this forum told me it should be the 5UL-12180. What is the correct part number for the 2004?

  • wr171

Posted December 16, 2004 - 05:27 PM

#5

I was curious about this as well so I went to the Yamaha web site and compared the part numbers between the YZ cam and the WR cam. It appears that they share the same intake cam but have different exhaust cams. I am considering changing the exhaust cam in my 2004 WR450 to the YZ cam. The bike has plenty of power but, like most folks, always want more.

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  • Robert_Brazil

Posted December 17, 2004 - 03:50 AM

#6

I have ordered the cam, will post a reply as soon as I ´ve tested it. Some like others think the bike is too aggresive. I liked it on my WR426 (which was easier as it does not require a new cam). The bike rev´s faster and has more power and torque. Although it becomes wilder, by no far the power kick in is as aggresive as on a 2-stroke 250, its still a 4-stroke and that´s good.

  • TriCal

Posted May 22, 2011 - 07:51 PM

#7

How did the cam work out? I have an 08 WR450 and broke an intake valve while riding in Baja a couple of weeks ago. I saw a YZ complete head for sale and was wondering if this would be a good option for me.
Cheers.

  • tribalbc

Posted May 22, 2011 - 08:30 PM

#8

How did the cam work out? I have an 08 WR450 and broke an intake valve while riding in Baja a couple of weeks ago. I saw a YZ complete head for sale and was wondering if this would be a good option for me.
Cheers.


That would work great if it's an 06-09 YZ head. But you will probably lose your estart.

  • TriCal

Posted May 23, 2011 - 07:45 AM

#9

Do you mean the decompression leaver mounted over the clutch leaver? I never use that anyway. Would I need to change anything else to work better with the YZ head?

  • tribalbc

Posted May 23, 2011 - 08:36 AM

#10

Do you mean the decompression leaver mounted over the clutch leaver? I never use that anyway. Would I need to change anything else to work better with the YZ head?


You have an 08 right? If so that is a hot start conected to the carb, not a decompression lever.
07's on have auto decompression and the pin is too long on the YZ exhaust cam, causing it to dump too much compression for the estart to work. It still can work, just not 100%.
If your WR exhaust cam is fine you could throw that in there and have fine estarting. But the YZ cam is a funner ride, more hit, and an easy kickstart.

Otherwise it's a bolt on assuming you already have your AIS disabled.

  • MaxPower

Posted May 23, 2011 - 07:16 PM

#11

I have ordered the cam, will post a reply as soon as I ´ve tested it. Some like others think the bike is too aggresive. I liked it on my WR426 (which was easier as it does not require a new cam). The bike rev´s faster and has more power and torque. Although it becomes wilder, by no far the power kick in is as aggresive as on a 2-stroke 250, its still a 4-stroke and that´s good.

[COLOR="Green"]to me it didnt make the bike too aggressive
the YZ cam made the bike run like it should. Right from start up I could hear a difference
Detuning a race motor doesnt make it tractable for the woods necessarily. In my opinion a detuned motor just runs like crap.The WR motor still has the big flywheel and different map
I wish I could change something they put on my WR that would make it lose 50 pounds [/COLOR]
.




 
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