2006 YZ450 head or cams on a 2007 WR450

[coombscorey]

Hello, first posting on Thumper Talk.. I know there already has been been talk about this but.. I have a 2007 WR450f that I would like it to produce more of a pouch. I have purchased a 2006 YZ450F complete head. I was wondering if I should use the whole head or just the exhaust cam. I will also been adding a white brother slip on exhaust that I purchased used. Any useful help would be appreciated.   

[knuckleduster271]

Hello, first posting on Thumper Talk.. I know there already has been been talk about this but.. I have a 2007 WR450f that I would like it to produce more of a pouch. I have purchased a 2006 YZ450F complete head. I was wondering if I should use the whole head or just the exhaust cam. I will also been adding a white brother slip on exhaust that I purchased used. Any useful help would be appreciated.

The head is pretty much the same aside from the yz not having the ais port. It won't offer anything over the wr head in performance. The cams are a direct swap, the 06 cams will show a pretty big improvement over the stock wr cams. I have the 06 yz cams in my 07 wr450 and the midrange "hit" is much more aggressive. The 06 cams are the gnarliest ones from the factory. They were redesigned in 07 to soften the hit.

[FORMA MOTO]

I ported my head and used the '07 cam, and there is more power everywhere, with no hit, and no substantial over-rev.

Originally I had the HotCams YZ spec cams, and they have a big upper mid hit, but not any bottom; so much so that the bike would not pull the next gear on a moderate hill.

With the '07 cam I can always run a gear high and still have pulling power, or the right gear and be FAST. 

 

I highly recommend against the HotCams YZ spec cams.

[coombscorey]

Thanks for the information, From your advise i'm just going to do the cams and not the head. Would you have a suggesting on what jetting I should be running with the new cams and slip-on exhaust.

 

Thanks!

[knuckleduster271]

Thanks for the information, From your advise i'm just going to do the cams and not the head. Would you have a suggesting on what jetting I should be running with the new cams and slip-on exhaust.

Thanks!

I could probably get you in the ballpark.

What elevation are you at?

If the free mods havnt been done yet I would consider doing that as well as removing the ais system.

Edited October 14, 2015 by knuckleduster271

[coombscorey]

^{I'm base at 2700 ft (Boise ID) but ride anywhere between 2500 thru 5000 ft depending on where i'm at.} 

 

^{Thanks for all your help!}

[FORMA MOTO]

Thanks for the information, From your advise i'm just going to do the cams and not the head. Would you have a suggesting on what jetting I should be running with the new cams and slip-on exhaust.

 

Thanks!

165/45/ncvs 4th/R&D fuel screw/ACV stock/ stock everything else.

You must de-restrict the intake and exhaust.

 

If there are more than 150 hours on the bike, get a new stock replacement needle jet too.

 

If you want the best throttle response possible, update the accelerator pump system to 2008 Honda specs.

 

http://www.crfsonly.com/catalog/product_info.php/cPath/138_147/products_id/3932

 

I would recommend changing the entire pipe, as the stock header is designed to go with the stock muffler, and is small in diameter.

 

Be prepared for massive wheelies.............

[coombscorey]

Krannie - thanks for all the information. The accelerator pump will fit the WR Yamaha? 

[FORMA MOTO]

Krannie - thanks for all the information. The accelerator pump will fit the WR Yamaha? 

Same basic carb on virtually all brands............