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



68 replies to this topic
  • fixitandy

Posted August 25, 2013 - 06:55 PM

#41

Great work, n16ht5, I have been cam curios for quite a while, but all the intell seemed clouded, I am gonna have a crack at this one too, I love tuning especially free ones, hold it wide open guys! ROOSTA out.

  • Krannie McKranface

Posted August 25, 2013 - 09:05 PM

#42

2007 and later don't allow for the 'exhaust cam retard' trick.

 

OEM YZ cams will eliminate your decompressor system, making it a kicker-only bike.

 

Hot Cams YZ spec cams for the WR will give you that YZ power, ONLY if you port the head a bit and add a High compression piston (just 12.8:1).

The stock head does not flow well enough to accept the YZ exhaust cam spec, and will actually hurt the power....even with the YZ header and exhaust.

 

The easiest and cheapest method is to keep the stock WR exhaust cam, and add the Hot cams YZ spec intake cam, along with a free-flowing exhaust. 

That gives you about 3-5 hp across the board over an un-corked and well set up stock WR with a stock modified pipe.

 

I will be taking my motor apart to remove the Hot cams YZ spec exhaust cam next week............ or porting the head, I can't decide.....



  • stevethe

Posted August 26, 2013 - 07:01 AM

#43

2007 and later don't allow for the 'exhaust cam retard' trick.

 

OEM YZ cams will eliminate your decompressor system, making it a kicker-only bike.

 

Hot Cams YZ spec cams for the WR will give you that YZ power, ONLY if you port the head a bit and add a High compression piston (just 12.8:1).

The stock head does not flow well enough to accept the YZ exhaust cam spec, and will actually hurt the power....even with the YZ header and exhaust.

 

The easiest and cheapest method is to keep the stock WR exhaust cam, and add the Hot cams YZ spec intake cam, along with a free-flowing exhaust. 

That gives you about 3-5 hp across the board over an un-corked and well set up stock WR with a stock modified pipe.

 

I will be taking my motor apart to remove the Hot cams YZ spec exhaust cam next week............ or porting the head, I can't decide.....

 

Interesting didn't know the porting was different between yz and wr heads.

.



  • n16ht5

Posted August 26, 2013 - 07:45 AM

#44

2007 and later don't allow for the 'exhaust cam retard' trick.

 

OEM YZ cams will eliminate your decompressor system, making it a kicker-only bike.

 

Hot Cams YZ spec cams for the WR will give you that YZ power, ONLY if you port the head a bit and add a High compression piston (just 12.8:1).

The stock head does not flow well enough to accept the YZ exhaust cam spec, and will actually hurt the power....even with the YZ header and exhaust.

 

The easiest and cheapest method is to keep the stock WR exhaust cam, and add the Hot cams YZ spec intake cam, along with a free-flowing exhaust. 

That gives you about 3-5 hp across the board over an un-corked and well set up stock WR with a stock modified pipe.

 

I will be taking my motor apart to remove the Hot cams YZ spec exhaust cam next week............ or porting the head, I can't decide.....

 

 

Been hitting the bottle a little hard, my friend? Once you get it jetted right it rips. I have proven that E start works with it as well...

 

when I check the valves again this spring I will add a YZ intake cam... because you can never have enough!



  • n16ht5

Posted August 26, 2013 - 07:53 AM

#45

Forgot to mention.. went for a 110mi DS ride, averaged 55mpg.  

 

9568756682_580e0c21a2_b.jpg



  • beezer

Posted August 26, 2013 - 08:20 AM

#46

I was told YZ and WR heads are the pretty much the same and interchange.  The WR has some air injection holes.

 

My WR is a very fast bike.  It runs like a YZ with a heavy flywheel.



  • Parx_400

Posted August 27, 2013 - 08:30 AM

#47

Not sure on the 07 bikes but my 06 runs much better with the yz exhaust cam. Starts just fine cold with a hair of gas. I am 100% sure it's timed correct, 13 pins. Bike has a full pc exhaust, danatek cdi, jd jet kit, and relocated battery so the whole top of the air box is open like a yz. The mild cdi setting is great for slow tight sections. The more advanced ones are great for wide open sections. I will need to rejet soon as it gets cool.

  • Krannie McKranface

Posted August 27, 2013 - 04:28 PM

#48

Not sure on the 07 bikes but my 06 runs much better with the yz exhaust cam. Starts just fine cold with a hair of gas. I am 100% sure it's timed correct, 13 pins. Bike has a full pc exhaust, danatek cdi, jd jet kit, and relocated battery so the whole top of the air box is open like a yz. The mild cdi setting is great for slow tight sections. The more advanced ones are great for wide open sections. I will need to rejet soon as it gets cool.

Exahust cam from a YZ, or YZ timing on a WR cam?



  • Parx_400

Posted August 27, 2013 - 04:30 PM

#49

It's a yz cam.

  • KennyMc

Posted August 27, 2013 - 04:30 PM

#50

He is referring to my bike as his example.  When I took my bike in for it's first ever manhandling of it's internals, I had the YZ Hotcams designed for the WR installed along with new valves and piston.  This was earlier this year.  My piston would not be considered a high compression piston as I went from a 12.3:1 to a 12.5:1.  The port job was just a mild clean up job of rough edges from the castings.  I have a 172 main, 48 pilot and, well, can't remember the rest cause I put them in back in '07 before I ever rode the bike and haven't touched them since.  I have just a slip-on Yosh exhaust and an opened up air box with a Twin Air filter.

 

My bike has and continues to run fantastic.  I had never even had the valves checked before I took it into ASRacing for the work this year.  I just figured it was time and I wanted to get a bit more umph outta the bike.  I have been real happy with the performance increase and would recommend it to anyone. :ride:



Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • Parx_400

Posted August 27, 2013 - 04:36 PM

#51

Oh and when I say starts cold we are talking Sacramento summer cold as in its over 90 out. Sure it will be hard to start cold in the winter. My last one also had the 4 cell battery pack relocated they don't like to get cold.

  • Krannie McKranface

Posted August 27, 2013 - 06:38 PM

#52

I am starting to wonder if the flow characteristics from one head to another (really wide flow tolerances) might be the cause of some having great and some having poor results with the HC YZ cams.

I've counted (4) successes (" it runs better and has more power everywhere") , and (3) failures (harder starting, peaky power, bad throttle response"), not counting mine or Kens results.

Everyone claims to be using the same 13-pin timing scheme too.

 

Even though HC claims to have checked the degree-ing of both cams, I'm not so sure the problem doesn't just lie in poor QC from HC ??

 

WTF.



  • n16ht5

Posted August 28, 2013 - 06:22 AM

#53

try retarding your Wr cam

  • Parx_400

Posted August 28, 2013 - 08:28 AM

#54

The bike had more slow putting tractor power before i did the cams I think. I might be that the mid range hit is so much harder It feel like the low end has been lost a tad. I would need to ride two bikes back to back in order to be sure. I have mine geared 15/48 for dual sport and open deszert now. When I had the stock gearing with all the mods and the cdi set more advanced the bike was a beast. I have not set the TPS or anything yet. 

 

A guy I know in town has a stock 05, I need to ride his and then mine and see how it feels. To be honest I never road my 2000 my 2005 or my 2006 with the stock WR cam setting for more than a hour before doing all the mods. 



  • Krannie McKranface

Posted August 28, 2013 - 03:21 PM

#55

The bike had more slow putting tractor power before i did the cams I think. It might be that the mid range hit is so much harder It feel like the low end has been lost a tad. I would need to ride two bikes back to back in order to be sure. I have mine geared 15/48 for dual sport and open deszert now. When I had the stock gearing with all the mods and the cdi set more advanced the bike was a beast. I have not set the TPS or anything yet. 

 

A guy I know in town has a stock 05, I need to ride his and then mine and see how it feels. To be honest I never road my 2000 my 2005 or my 2006 with the stock WR cam setting for more than a hour before doing all the mods. 

 

Well I know my low end has dropped 10%, and my power does not come on until 6500 rpm, and when it does, you either wheelie or spin the tire, unless you are just cracking the throttle. 

The power is much fun on the street, but useless for single track. I have to ride short shifting (and shifting very often) to keep the rear wheel connected. The problem is, it won't accept much throttle in the lower rpms, so it's hard to accelerate without just using the trans to gain speed.


Edited by Krannie, August 28, 2013 - 03:22 PM.


  • KennyMc

Posted August 28, 2013 - 09:39 PM

#56

Bill, what gearing are you running on your bike? I think I have a 49 on back and stock on front. I know our bikes run different, but mine runs real well up in Kennedy Meadows which is tight single track and is in high elevation from 7,500-9,600.

Also, for the back shock, is there a year of YZ that won't fit? Should I just stay around the '07-09 year?

  • Krannie McKranface

Posted August 28, 2013 - 09:45 PM

#57

Bill, what gearing are you running on your bike? I think I have a 49 on back and stock on front. I know our bikes run different, but mine runs real well up in Kennedy Meadows which is tight single track and is in high elevation from 7,500-9,600.

Also, for the back shock, is there a year of YZ that won't fit? Should I just stay around the '07-09 year?

 

 

I have 14/50 gearing

 

I'm not sure about the shock.....I think anything from '05 to '10 will fit, but starting with '06 it's SSS. 



  • KennyMc

Posted August 28, 2013 - 11:04 PM

#58

I have 14/50 gearing
 
I'm not sure about the shock.....I think anything from '05 to '10 will fit, but starting with '06 it's SSS.

Ok, cool. Took the bike out for the first time last weekend with the YZ forks. Just a cruise of a ride in Big Bear. Did notice a difference for the better. Want to try them in higher speed stuff. But that made me want to get the back shock as well though.

  • Krannie McKranface

Posted August 28, 2013 - 11:39 PM

#59

Ok, cool. Took the bike out for the first time last weekend with the YZ forks. Just a cruise of a ride in Big Bear. Did notice a difference for the better. Want to try them in higher speed stuff. But that made me want to get the back shock as well though.

 

Yeah, it will be a 'must have' with the YZ forks, especially at speed. 

I haven't gotten the valving just right yet, but I can jump those steep rain diversion 'jumps' now at the highest speed my balls will let me.

Before I had to roll them or get chucked of my line, or, bottom out...



  • KennyMc

Posted August 29, 2013 - 12:13 AM

#60

Yeah, it will be a 'must have' with the YZ forks, especially at speed. 
I haven't gotten the valving just right yet, but I can jump those steep rain diversion 'jumps' now at the highest speed my balls will let me.
Before I had to roll them or get chucked of my line, or, bottom out...

At this time I don't think I'm even gonna mess with springs or anything. Being sprung for a 180lb rider but a bike that is 25lbs lighter, I'm thinking the springs might be about right for a 205lb rider. Close enough for now.

The one thing that is a concern is the plastic ics free piston. I've heard they are a weak spot. There's some billet ones out there that I might get and have installs when I do a oil change.




 
x

Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.