07 WRF... retard cam, hotcam, or yz450f cam?

[n16ht5]

since I am in adjusting my valves I want to get some more power with cam mods. I seem to have a hard time finding a concrete answer as to which is the best power to money cam mod to do.

retard the exhaust cam one tooth

yz450f exhaust cam

hotcam

+yz450f intake cam>??

I have this link to retard the stock cam a tooth.. which requires decomp pin milling...

http://www.yfzcentral.com/forum/32-yfz-powertrain/46023-yfz450-cam-mod.html

what should I do? Any of you WA guys want some free beer?

Chris

[n16ht5]

okay well I'm going with the retarded wr cam. I ground 1mm off the decomp pin and I am going to reinstall tomorrow. Hopefully no valve parties ensue...

[Bandit9]

Have you done the stiffer Accelerator Pump spring yet? Like the Merge Racing AP spring?

[n16ht5]

No, but I did the O ring mod. carb mods, YZ head pipe, lexx exhaust, desmogged, de-corked, etc..

Edited November 18, 2012 by n16ht5

[Bandit9]

Just checking b/c I thought the extremely improved throttle response with the stiffer AP spring, YZ complete exhaust, and clean jetting made it just right for single track. I have to be around 51-53 HP right now.

I was under the impression that you couldn't do the retard on the newer WR's, and that replacing it with the OEM YZ cam or Hotcam was the only way. But then you could possibly run into problems with the E Start not working, which is why I didn't mess with the cams. I like my E Start, especially with the Shorai battery.

You are a lot braver than I am. Very interested in how this turns out, keep us posted.

Ain't no party like a valve train party!

Edited November 18, 2012 by Bandit9

[n16ht5]

hmmm.. what does the stiffer spring do vs the o ring????

[Bandit9]

Supposed to accomplish the same thing. However O rings stretch easily and would diminish the response over time. Where as the spring is consistent for quite a while I would imagine. But since you already know what it feels like by doing the O ring mod, it probably wouldn't give you the power you are after.

Edited November 18, 2012 by Bandit9

[Bandit9]

Might try the AP spring anyway since it is cheap, I paid $5 for this little wonder at CycleGear. Maybe your O rings are worn out and this would give you the kick that seems to be missing.

[n16ht5]

i used a small zip tie, no wearing out

[n16ht5]

well it's back together and running again with the ex cam retarded a tooth and valves shimmed back in spec. Dumping rain and I need to rewire a few things so I'll try to ride it later. I'm glad this thing is so fun to ride because it really kills the time trying to work on it!!

few things I learned

-give yourself 30 minutes just to get the valve cover off. then take a break and come back and try it again. very tight clearance

-make sure you stuff lots of rags over the motor.. lots... somehow a c clip managed to sneak past the rags I had stuffed in there and migrated down all the way to the flywheel.

-there are two little c clips that love to go flying when you pop off the valve retainer cover deals... no matter how gentle you pry them.

[MANIAC998]

Ain't no party like a valve train party!

This is an instant classic!!! And this should be a "sticky"!!!!

[Bandit9]

Thanks for the tips. You get to ride it today?

[n16ht5]

Thanks for the tips. You get to ride it today?

finally got it all back together. It runs like a raped ape! I just took it for a quick spin down the driveway a few times, dark and raining out.. but it runs better than I was expecting... much more snap right off the bottom. I need to re-jet the carb now.

Also, the E start works better than before! It doesn't seem to hang on the compression stroke as much now. Best free mod so far.

pics:

-starting...

valves have moved... probably not a great thing, but the bike has 150+ hard hours and this is the first time they needed to be adjusted

exhaust cam decomp pin

pin out it measures .940

dremeled down .040 or 1mm.. then rounded and sanded smooth with a few grades of sandpaper to a shine.

back together, greasing bolts (swingarm bolt) if you haven't ever greased yours, do it. there are pics on the xr400 section of a guy who resorted to cutting off his entire swingarm from a frozen bolt.

not even a full season on this skid plate.. call that a good year ?

now my lights and accessories only come on with my ignition too ? (relayed the wiring harness)

Edited November 22, 2012 by n16ht5

[Bandit9]

Nice work!

[beezer]

You can't get any better than free.

I put a YZ exhaust cam in mine and the e-start hangs up on a compression stroke sometimes but it made a huge difference in power from top to bottom.

Good work!

[Bandit9]

Yeah this is the first I've seen be able to do it like this.

[MANIAC998]

How is the power output? Does the power come on to strongly? With the limited traction out here, smooth power is good power, so I was just wondering. Thanks!

[Bandit9]

Also after you get a few hours on it, let us know how the E start is working.

[n16ht5]

went for a trail and ds ride today... oh man it rips!! it tractors like an xr but pulls out like a yz450 on top. e start worked every time all day. I cant believe how much better it runs.

do this mod!

[still2smokin]

went for a trail and ds ride today... oh man it rips!! it tractors like an xr but pulls out like a yz450 on top. e start worked every time all day. I cant believe how much better it runs.

do this mod!

I didnt see in the link where it said anything about grinding down the decomp pin. Maybe I missed it but does this need to

be done to all WR's ?

I am seriously thinking about doing this.