To YZ time or not to YZ time, that´s not the question anymore.

I own a WR450F that is considerably milder than my previously YZ timed WR426 Although I mostly do woods racing at competive riding level and the bike provides abundant torque and deliverable power, I like the YZ faster revving YZ curve. It is my impression that the engine was designed for YZ timing and the WR timing curve was just done to make things a little less "spectacular", but it doesn´t feel like YZ timing. Moreover YZ timing is also easier and yes I´ve jetted correctly.

I am about to invest in a 450F YZ cam, yet as I am based in Brazil my dealer doesn´t have these off the shelfs and e-bay purchasing is complicated for some sellers that don´t sell abroad. Is the to be expected change similar to changing the 426 timing (the 426 had a higher compression rate also that spiced things up compared to the 450, didn´t it?)

Can any one give me the name and telephone number of an organized Yamaha dealer in the states where I can buy the cam, and what price is reasonable?

Also, besides the camshaft do I need other parts, such as shims to adjust valve clearance, or nothing else as just the timing angle changes?

Thanks for your help!

Robert Email them a part #, easily gotten from and one of the John' s will reply with the lowest price you'll find on the internet...:cry:

Did you cut the throttle-stop? The WR450 is NOT a mild bike! :cry:

You will see the same quicker reving harder hitting mid range and top end if you put in the YZ exhaust cam in your WR. I would just order the part from your dealer in Brazil. It may take a few weeks but it makes the business of shipping and paying a lot simpler. $162.00 US is the list price for the 03 or 04 YZ part. Doesn't your dealer order parts for customers with bikes in your area? I really dont see the reason you need to buy from E-Bay or the US. Our dealers dont stock anything anyway. They all come from the Yamaha warehouse and dealers get their parts orders delivered once a week. :cry:

Dear Rich, this is very helpful, I already contacted them and the prices are fair!

Remaining Questions

1) the part I need to exhange is the 5TA-12180-00-00 (which according to the Yamaha Part List is the EXHAUST CAM SHAFT of the YZ450F, right?

2) besides the camshaft, do I need anything else (parts?) to make the exhange from WR to YZ timing. Washers to adjust valve clearance...?

3) Where (in the ThumperTalk forums) can I find a step-by-step description how to exchange the camshaft.


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