WR to YZ cam timing, pro's & cons please!


17 replies to this topic
  • 6fiddy

Posted September 01, 2005 - 11:26 AM

#1

Ive done the free mods on the 02 wr426 except the exhaust cam timing mod.
I ride trails, not tracks, woods, not desert. I would rather not open up the top end and do the mod and then be dissapointed. What about the wr450 cam upgrade, or a yz450 upgrade? :D Pros and Cons ? Need the INFO! Is anyone sorry that they did the yz timing or the 450 cam upgrade? :D :D Let me hear you! THANKS !!!

  • jwriott

Posted September 01, 2005 - 12:43 PM

#2

I just rotated mine on my 01 WR426. I think the mid range and top end were much better especially in sand where I needed to get on it harder. I loved the bike with YZ timing.

  • byggd

Posted September 01, 2005 - 01:21 PM

#3

Ive done the free mods on the 02 wr426 except the exhaust cam timing mod.
I ride trails, not tracks, woods, not desert. I would rather not open up the top end and do the mod and then be dissapointed. What about the wr450 cam upgrade, or a yz450 upgrade? :D Pros and Cons ? Need the INFO! Is anyone sorry that they did the yz timing or the 450 cam upgrade? :D :D Let me hear you! THANKS !!!

I have the same bike and did the upgrade and I love it. Easier to start with the auto decompress, it has more throttle response down low which is nice in tight stuff, and even though it's a YZ cam it smoothed out the power band. I have a spec sheet someplace showing how to do the install and it shows the results on a dyno readout. Here is a thread where I asked why not the wr cam http://www.thumperta...0&highlight=cam You wont be disappointed IMHO :eek:

  • kincade

Posted September 01, 2005 - 01:25 PM

#4

Ive done the free mods on the 02 wr426 except the exhaust cam timing mod.
I ride trails, not tracks, woods, not desert. I would rather not open up the top end and do the mod and then be dissapointed. What about the wr450 cam upgrade, or a yz450 upgrade? :D Pros and Cons ? Need the INFO! Is anyone sorry that they did the yz timing or the 450 cam upgrade? :D :D Let me hear you! THANKS !!!


I did the cam timing on mine, and I"ll say this; GOOD for sand, BAD for trails. If you like high speed desert roads, sand, etc, the power is great. But it makes it definitely harder to control at lower speeds. I know there are a few others that feel that way here too.

Also; difference for me wasn't in the top end; it was the bottom. The bike is a LOT stronger on the bottom with the cam.

  • simon@vic

Posted September 01, 2005 - 07:22 PM

#5

GOOD for sand, BAD for trails.


i disagree.
i primarily ride very tight trails on steep terrain {that is all we have around here}. i found the zy cam to be way better everywhere. more power and torque from 1000 to 10000 and more snap. the 5 valve motor was designed for an open air box, free flowing exhaust and the YZ cam.

too me it is painful to see such a nice motor all choked up, de-cammed, ais-ed, and all the other crap they do to detune the motor.

i say if you cant hold on, get a 250, mod it and at least then you can ride at 13000rpm :D :D

  • kincade

Posted September 01, 2005 - 09:47 PM

#6

Well, that is EXACTLY what I was saying. MUCH more power down low, which isn't always good. I don't know what the rocky trails are like there, but more power isn't always better here. When you have a lot of traction, more power down low doesn't help at all. Not to mention it will stall much easier w/ the YZ cam; that's why it is there in the first place.

If a significant increase in power down low and an increased tendency to stall down low when lugged won't bother someone, it is a good mod. It all depends on the use and terrain of the rider.

For me, I wish I had a switch; to turn it off and on. 1/2 the time I'd love it; but the drawbacks on tight singletrack and high traction situations outweigh the benefits for me.

  • kincade

Posted September 01, 2005 - 09:58 PM

#7

A few interesting reads for you:

http://www.thumperta...6&highlight=Cam

And another:

http://www.thumperta...3&highlight=Cam

One more:

http://www.thumperta...5&highlight=Cam

And the last:

http://www.thumperta...6&highlight=Cam

  • Hamish

Posted September 02, 2005 - 04:23 AM

#8

You'd want to be a better than average rider to take advantage of a YZ timed 426 on the tight trails and hillclimbs . It's probably a waste of time doing the YZ timing without a free flowing exhaust. The YZ450 cam, on the other hand, make unco dudes like myself look like they know what they are doing. The YZ450 cam isnt slow, but isnt violent either. It puts the power to the ground smoothly, from idle to the limiter. It works perfectly for technical hillclimbs. When I had my 426 YZ timed, it seemed to spend a lot more time sideways on the limiter destroying the back tyre. Fun yes, predictable, no.

  • byggd

Posted September 02, 2005 - 04:25 AM

#9

A few interesting reads for you:

http://www.thumperta...6&highlight=Cam

And another:

http://www.thumperta...3&highlight=Cam

One more:

http://www.thumperta...5&highlight=Cam

And the last:

http://www.thumperta...6&highlight=Cam

Your examples are of 450 owners and the bikes are different, believe me, I've owned both. I never tried just yz timing my 426 but adding the 03 yz ex cam was probably the best mod I ever did :D These big thumpers tend to stall down low by nature, and I ride a lot of tight stuff, so I also added the Rekluse.....no more stalling :D

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • banffboy

Posted September 02, 2005 - 06:27 AM

#10

i disagree.
i primarily ride very tight trails on steep terrain {that is all we have around here}. i found the zy cam to be way better everywhere. more power and torque from 1000 to 10000 and more snap. the 5 valve motor was designed for an open air box, free flowing exhaust and the YZ cam.

too me it is painful to see such a nice motor all choked up, de-cammed, ais-ed, and all the other crap they do to detune the motor.

i say if you cant hold on, get a 250, mod it and at least then you can ride at 13000rpm :D :D


Exactly what Simon said :D

  • R_Little

Posted September 02, 2005 - 06:49 AM

#11

My 400 with yz timing is faster on top but lost a bit of lowend snap right off the bottom.

It's harder for me to yank wheelies right off idle and the midrange hit makes it harder to keep them up.

Yes, it does pull my friends WR timed bike in the sand even with a Q pipe!

I'm getting a 444kit and an auto-d cam as we speak...Can't wait!!

  • kincade

Posted September 02, 2005 - 08:19 AM

#12

My point is that not all agree that the YZ cam mod is good for slow speed stuff; the original thread poster should be aware that its perhaps a 50/50 split on whether the cam mod is good. Some great riders like Indy took theirs back out.

Now it's not an expensive mod; I got my cam for $94 shipped to my door. So if the poster didn't like it, he can always take it out. But he should know that not all have been happy with the results.

  • Cedric

Posted September 02, 2005 - 08:29 AM

#13

I'd have to agree with my fellow canucks, the YZ timing mod is great, and I am never putting mine back to WR time - and I almost exlusively ride tight singletrack in the mountains. Having that instant bark can be a real life saver when you need it, and I have never found it to be a handicap, plus it's just more fun. It might be a bit more tiring to ride, but it's just another good reason to stay in shape. :D

  • Dan_Lorenze

Posted September 02, 2005 - 08:45 AM

#14

Pros: -You FEEL like you're going faster and the bike has more "snap"

Cons: Less throttle control, less traction, more wheel spin, less bottom end power delivery.

I've have plenty of time to experience YZ timing on my old 01 426, yes, it was fun to twist the throttle cuz it really wakes the bike up.. But, sadly... That power goes to waste when you're riding trails or trying to negotiate a technical section.. Wheel spin is a horrible character to have while riding trails.

There was a big change in the power delivery from the 2002 WR426 and the 2003 WR450, guys complained how the new 450s are slow and too mellow with very little hit, (they still complain). It's because Yamaha engineers figured out that a smoother more gradual power delivery would result in a better "Offroad" bike for offroad conditions. There's a reason why the power is mellowed just like the power delivery on the infamous 03 YZ450.. Even for motocross it was just too much of a good thing.

I completely disagree with those who feel their bikes are faster on trails with YZ timing.. I personally feel it sucks for offroading.. If you want to MX your WR buy a YZ, those things are SWEET...

:D

  • jwriott

Posted September 02, 2005 - 02:23 PM

#15

Pros: -You FEEL like you're going faster and the bike has more "snap"

Cons: Less throttle control, less traction, more wheel spin, less bottom end power delivery.

I've have plenty of time to experience YZ timing on my old 01 426, yes, it was fun to twist the throttle cuz it really wakes the bike up.. But, sadly... That power goes to waste when you're riding trails or trying to negotiate a technical section.. Wheel spin is a horrible character to have while riding trails.

There was a big change in the power delivery from the 2002 WR426 and the 2003 WR450, guys complained how the new 450s are slow and too mellow with very little hit, (they still complain). It's because Yamaha engineers figured out that a smoother more gradual power delivery would result in a better "Offroad" bike for offroad conditions. There's a reason why the power is mellowed just like the power delivery on the infamous 03 YZ450.. Even for motocross it was just too much of a good thing.

I completely disagree with those who feel their bikes are faster on trails with YZ timing.. I personally feel it sucks for offroading.. If you want to MX your WR buy a YZ, those things are SWEET...

:D


Oh, what do you know, :D

  • RLucky82

Posted September 02, 2005 - 03:38 PM

#16

I have always liked the predictable power delivery of my WR400 and if I wanted YZ timing and power I would have saved a few hundred $ and bought a YZ :D

  • yamahaMum

Posted September 03, 2005 - 03:40 AM

#17

hmmm.... I thought that the yz timing was wicked and even today i was blown away by the snap of power in 4th gear, but i must agree that i have 'suffered' more wheelspin.... which i thought was a good thing showing more power, but common sense tells you that a spinning wheel will not project you with the same speed as one that grips for longer before breaking traction...
i'm sure i can see my rear tyre wearing by the day.
I love the yz timing, it just feels more animal. not a lot of logic in that.
definitley starts better and without hotstart too, but since did pipe mod that i believe makes it easier to start also.

bloody hell,not that old battle between adrenalin and practicality again...............should i change it back? should i leave it?.........
aaaaaaaaaaaaaaaaaaaaaaaaaaghhhhhhhhhhhhhhhhhhhhhhhhhhhh

  • dominator426

Posted September 03, 2005 - 10:53 PM

#18

I got the best of both worlds by switching to YZ timing with 2 base gaskets, while attempting to reduce its octane requirement. I still have to mix 30% 100LL with 91 pump gas. I got a smoother and more tractable low end with better top end, resulting in a wider and stronger powerband. My Power Now Valve and FMF Power Bomb SX header also helps strenghten low end response.




 
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