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slowngreen

A few WR450 questions.

10 posts in this topic

Ive been reading through the stickies as well as doing some google searching and not really found the answers Im looking for.

 

1. On the "free mods" for 05+, are they relevent for all the wr450's up till 2012?

 

2. Do the free mods alone bring the power any where near the power of a carbed yz450f lets say 06-09?

 

and finally...

 

3. How are the 2012's and newer as far as being really limited in power compared to the FI Yz450f's? Same as in the carb bikes? Would some simple stuff like full exhaust and a programmer make it any where near a yz450's stock power? 

 

thanks in advance guys. Im just looking around at different bikes and trying to narrow down what I want. Im not worried about which would work better in what situation at the moment but rather can the wr be fairly easily and cheaply made as powerful as the yz's. 

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1. Yes

 

2. No. Much heavier flywheel, trans, clutch, make it rev slower. Different exahust cam, different ignition, different airbox, jetting, and pipe, make it tamer in delivery and HP.

    To get it to be close, you must do some 'non-free' work to it. A pipe and good carb tuning make a big bite out of the difference.  The suspenson of the pre- '12's is the major limiting factor.

 

3. YZ's and WR's are not the same bike anymore. That will change in 2016, but the 2012+ WR and the 2014+ YZ are worlds apart in performance on all levels.

    The new YZ is no longer 5 valve head, it has MUCH larger porting in the head, etc etc, for more power. 

    You can buy the full WR-GYTR parts suite, and get a monster powered bike, if you want to spend $9k for the privildge....good tuning and mild head work is all it needs to be really fast.

    Compared to a 2007 YZ, the WR can made to be close, accept for the 'feel', and  the weight.  The 2012 upgraded suspension and frame are the big difference.

Edited by Kah Ran Nee
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You can exchange cams from (IMO almost) any YZ into a WR, specially the exhaust cam would/ could make a difference..

and changing the jetting, would be the best to make it run faster, or try to change the flywheel,

stationary revs would go up about 300 - 500 revs, but my RXV idles @ 1700+ rpm..

 

or you wait for the 2016 WR.. which looks to be interesting..

I hope GET will get an injection module for that bike............ :goofy:

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You can exchange cams from (IMO almost) any YZ into a WR, specially the exhaust cam would/ could make a difference..

and changing the jetting, would be the best to make it run faster, or try to change the flywheel,

stationary revs would go up about 300 - 500 revs, but my RXV idles @ 1700+ rpm..

or you wait for the 2016 WR.. which looks to be interesting..

I hope GET will get an injection module for that bike............ :goofy:

Surely one bike being a 4 valve head and the other being a 5 valve head would make this impossible

"You can exchange cams from (IMO almost) any YZ into a WR"

I thought cams controlled the valves?

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as far as I know Y have the same 5 valve head as the WR..

 

a 2006 WR cam is exchangeable with a 2009 YZ cam...

 

of course, both must be 5-valve heads..

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From Wikipedia

September 8, 2009, Yamaha introduced its all new YZ450F with fuel injection . The engine is now rear-ward mounted, the crank rod angle has been changed to provide a more complete combustion, the 5-valve head is now a 4-valve head

Edited by iggs

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It's not the best idea to switch exhaust cams from a 06-09 YZ to WR. The decompression pin is different so you may have issues with the electric start when cold. The intake cam switch is fine. The exhaust cam can have the decompression pin machined down

1 mm to work.

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Thanks for all the answers guys. Summed it up for me very nicely especially Kah Ran Nee. Sucks that it takes so much to make one of them or the crfx for that matter any where near the power of the mx/sx versions. Atleast that narrowed some things/choices out of the way for me. Thanks again guys. 

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