YFZ cams in a Wr400f I did it!!!!!!!!

4 replies to this topic
  • ready fredy

Posted August 30, 2008 - 07:22 PM


I have seen a few posts here asking about using the YFZ 450 cams in 400s/426s
Well i am the ginny pig here and did it. I was not looking for big horsepower like the yz cams produce because here in texas we have alot of single track sand trails, Oh and did i mention we have alot of SAND here???????!!!!!!!!! So yz timing just causes more trouble than good for me. All i wanted was the newer Wr450 power which i believe to be very strong but smoother than the old 400/426s. Well i was supprised just how much power it has right off idle, Its a torque monster for sure. The auto decompressor was also a bonus but not a necessity since im kick start anyway and the decomp lever always works just fine. So the answer to your questions is yes it works well but it is equivelent to wr power not yz. I did some research and the hot cams part number is exactly the same for the YFZ450 and the Wr450. I know yamaha part numbers are different but this could be due to the decomp pin difference. Naturally you will have to reshim same as using the newer yzf cams because the base circle is just a little smaller than the old cams but this is not a big deal at all.

  • wr 400 mikky

Posted September 04, 2008 - 12:19 AM


glad to see people are sticking to wr timing, i just installed both hotcams,wr timing, i may try yz for a week or 2 tho to see what all the fuss is about

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  • ready fredy

Posted September 04, 2008 - 05:09 AM


Ive always loved the stock Wr power, around here its just perfect the way it is not too sleepy and not too aggressive. Like i have said here we have sand..sand..sand..sand and more sand!!!!!And in my opinion the yz timing will only slow you down. I agree its fun to wheelie up and down the street but here on the single track trails its impossible to keep the back end under control.It kills me to hear guys talk about roll on wheelies in 4th and 5th on the street, bring that bike in the woods and ill kill it in the first 1/2 mile!!!!!! These are fabulous enduro bikes not 1/4 mile drag racers!!!!!!! Every one who has raced in there lives knows you have to have the right horse power for the conditions in the woods not on the dyno!!!!!!1

  • ready fredy

Posted September 22, 2008 - 06:04 AM


An update on my findings, Well as a hurricane Ike victim i was bored out of my mind with no power or work for a week, So after riding this bike in the woods it still had a very agressive punch right off idle with the stock 400 intake cam so i happened to have the yfz intake cam also so i installed it and it took alot of that punch off and im more happy now. Remember i was looking for more enduro like power and i think im where i wanted to be now. Buit to be honest if i were still racing i think i would opt for a big bore 250f. But the 400+ bikes are still fun for my casuall weekend riding. Unfortunatly i probably wont be able to ride for months because im sure our national forrest is destroyed with fallen trees and ill have to get an update on the damage.

  • ready fredy

Posted January 28, 2009 - 09:01 PM


Ohhhhhh one last thing about this mod, Actually i thought it would be a detune but actually it was a fantastic tune up for the power i played back and fourth with the stock cams and the yfz450 cams were the real ticket it had great power right in the middle just where i like it.I would do it again in a new yourk minute!!!! But still Wr ish like i like it. The carbs arent crap either just tune them like the yzs of the same year and there good to go.


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