Help installing YZ Exhaust Cam on my 04 450

9 replies to this topic
  • Mrmonk7663

Posted June 14, 2010 - 12:13 AM


I have been working on my bike lately after it being down around a year. I have a YZ exhaust cam sitting in the garage that I want to install. I have searched this forum about this topic. I am trying to see if someone has a walkthrough or a guide on how to do this posted somewhere? Before you say "read your manual"...I already have. I'm looking for a dumbed down version that anyone can follow. I have read so many conflictiong stories on the cam install and the number of teeth between bla bla....I want to do this right the first time. Finally, with the cam install, what are the normal changes to jetting....up the main or simply adjust the fuel screw? Needle clip position change or no?

Thanks to anyone and everyone who helps me get the bike back on the road :-)

  • Mutu

Posted June 14, 2010 - 12:56 AM


How hard is it to follow the manual? Seriously?

dumbed down version?

pull tank off
pull cylinder head cover off
set to TDC
pull cam chain tensioner out
pull off cam shaft cover (dont drop clip down the engine)
pull cam out

Do the reverse to put it back together.

Jetting should stay the same. count pins before you remove cam. Should be 13 from memory. Put YZ cam back the same pins as the wr cam!!!

  • Mutu

Posted June 14, 2010 - 01:04 AM

do this, but leave 13 pins between the marks.

  • Mrmonk7663

Posted June 14, 2010 - 01:10 AM


Yes a dumbed down version just like u gave me is what I wanted :-). Perhaps an overview is a better word. Thank you for the info so quickly.

Oh yah, do I need to buy a new valve cover gasket or is it reusable?

  • T-Bone 426

Posted June 14, 2010 - 01:24 AM


make sure your tdc and the punch holes ( I and E ) line up flush on the face of the cam cover base . and also check your clearances while your there .and yes the gasket is reusable

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  • Mrmonk7663

Posted June 14, 2010 - 01:59 AM


Will do. One last thing for it advisable to put on a new cam chain?

  • Mutu

Posted June 14, 2010 - 02:41 AM


I wouldn't bother. You have to pull the flywheel to change it.

  • T-Bone 426

Posted June 14, 2010 - 02:44 AM


Some say to do it some say don't bother i do my 02 when i freshen up the top end piston n rings. every few years
there is also a good link which i cant find with all the good info and photos it was a wr/yz 250f thump site

  • CanadianWR450

Posted June 14, 2010 - 03:38 AM


Your E-Start may, or may after the YZ swap...lots of threads on here about that...

If thats still the original timing chain in the bike....change it.......

  • Mrmonk7663

Posted June 14, 2010 - 08:14 PM


Thanks for the replies guys. I think I will hold off on the chain swap, but ONLY because there will be a piston swap in a few months, at which time I'll take care of the cam chain and replace seals and things for the water pump for general preventative maintenance.


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