Hot Cams


13 replies to this topic
  • thomasj234

Posted July 22, 2009 - 01:32 PM

#1

I have a 2007 WR450F. I am thinking of installing the exhaust hot cam. Maybe both the intake and exhaust hot cam. What change in horse power can I expect to get from these changes (exhaust cam or both exhaust and intake).

Thanks,

Thomas

  • SJMC_DON

Posted July 22, 2009 - 01:57 PM

#2

I would do both...

I have no personal experience with Hotcams but did have YZ cams installed in my 07' for a while. Both int and ex and the power gains were awesome.

Unfortunately I suffered the "e-start no workee" after the YZ cam install so I contacted Hotcams and their tech support was very helpful... shoot them an e-mail and explain what you are looking for and I think they have options based on what your looking for in gains.

I have heard various things... some people have said the best gains are achieved by a more aggressive int cam only + hi-comp piston.

I know the YZ cam set made my WR a beast, I loved the tractor like pull from the bottom all the way thru the mid, it made the gears feel taller too.

Good Luck - I am personally interested in how it turns out... I have a new bike now and want to upgrade the cams and am definitely considering Hotcams over OEM YZ this time.

  • CanadianWR450

Posted July 22, 2009 - 04:10 PM

#3

I have Hotcams, both intake, and exhaust, on my '04, but I also installed a FMF Ti PowerCore at the same time (Had the stock exhaust, with spark arrestor, and end all removed, with stock cams before that), and the difference was amazing. Big power gains.
No E-Start issues at all.

  • thomasj234

Posted July 23, 2009 - 07:53 AM

#4

One more thing. I am a novice mechanic. Can I do the Hot Cam intall myself? Do I need a shim kit? The shim kit is kind of pricey. Do I need any special tools?

Thanks

  • SJMC_DON

Posted July 23, 2009 - 08:42 AM

#5

One more thing. I am a novice mechanic. Can I do the Hot Cam intall myself? Do I need a shim kit? The shim kit is kind of pricey. Do I need any special tools?

Thanks


I bought the shim kit years ago, I think I got it thru rocky mountain and it was $80.... it sucks because half og them you will NEVER use on a Yamaha. BUT it's a lot easier than intalling your cams, finding that you need to adjust and then going on the hunt for specific shims.... you'll be glad you have the kit when the time comes.

I strongly recommend a quality inch/lb torque wrench for cam cap bolts... over torquing these is a very common and costly mistake... I don't if you can search and find one that is 1/4" drive but that would be ideal.

I am somewhat mechanically inclined but the hardest part for me is always to get the timing chain tensioner re-installed.

Use your manual and hotcams instructions (I heard they are good:thumbsup:)

You can do it and then you'll be prepared to adj your valves for as long as you own a Yamaha 4T:ride:

  • erickdj

Posted July 23, 2009 - 12:24 PM

#6

I bought the shim kit years ago, I think I got it thru rocky mountain and it was $80.... it sucks because half og them you will NEVER use on a Yamaha. BUT it's a lot easier than intalling your cams, finding that you need to adjust and then going on the hunt for specific shims.... you'll be glad you have the kit when the time comes.

I strongly recommend a quality inch/lb torque wrench for cam cap bolts... over torquing these is a very common and costly mistake... I don't if you can search and find one that is 1/4" drive but that would be ideal.

I am somewhat mechanically inclined but the hardest part for me is always to get the timing chain tensioner re-installed.

Use your manual and hotcams instructions (I heard they are good:thumbsup:)

You can do it and then you'll be prepared to adj your valves for as long as you own a Yamaha 4T:ride:


I bought SJMC_DON's yz cams. I didn't have to adjust any valves, so there was no need for shims. $80 might seem steep for a shim kit, but each individual shim is pretty expensive around here, so it could actually be a good buy considering that and the fact that it's convenient to have spares handy at all times. He's right, DO invest in a nice quality 1/4 INCH/LB torque wrench, you're going to need it. I found a nice one from an online parts supplier for about $130 with free overnight shipping. I'm also somewhat mechanically inclined, but instead of the tensioner what I found difficult to install was the intake cam after the exhaust cam is put in place with the chain, but I did find what the "trick" to it was in the end. Must have been a issue of hand/finger size, because for me the cam tensioner was as easy as pie. The manual is absolutely necessary, if you didn't get one with the bike print one from yamaha's australia or europe website. The power gains are pretty darn good by the way, lots more on bottom/mid. My bike already had a full 06 yz exhaust, so top wasn't a problem. Not much issues with the e-start either, I've found the necessary procedure to make the e-start work 99.9% of the time.

  • 2in2out

Posted July 23, 2009 - 01:11 PM

#7

I bought SJMC_DON's yz cams. I didn't have to adjust any valves, so there was no need for shims. $80 might seem steep for a shim kit, but each individual shim is pretty expensive around here, so it could actually be a good buy considering that and the fact that it's convenient to have spares handy at all times. He's right, DO invest in a nice quality 1/4 INCH/LB torque wrench, you're going to need it. I found a nice one from an online parts supplier for about $130 with free overnight shipping. I'm also somewhat mechanically inclined, but instead of the tensioner what I found difficult to install was the intake cam after the exhaust cam is put in place with the chain, but I did find what the "trick" to it was in the end. Must have been a issue of hand/finger size, because for me the cam tensioner was as easy as pie. The manual is absolutely necessary, if you didn't get one with the bike print one from yamaha's australia or europe website. The power gains are pretty darn good by the way, lots more on bottom/mid. My bike already had a full 06 yz exhaust, so top wasn't a problem. Not much issues with the e-start either, I've found the necessary procedure to make the e-start work 99.9% of the time.


Which cam is best to apply with the grey wire mod? Has anyone done a comparison?

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  • WR450FGreg

Posted July 23, 2009 - 01:54 PM

#8

Do I need a shim kit? The shim kit is kind of pricey.


Thomas,

I have two complete HotCams shim kits here.
I don't need two.
I'd be happy to sell you one for $US50 plus shipping (from Australia, at cost) if you like.
PM me if interested.

Greg

  • erickdj

Posted July 23, 2009 - 08:28 PM

#9

Which cam is best to apply with the grey wire mod? Has anyone done a comparison?


Never tried a combination of only one yz cam at a time. I'd just start off by getting both if it's financially doable for you. That way you make sure the bike makes power everywhere in the rev range. But go ahead and do the grey wire mod even without the cam swap, it will give your bike more snap.

  • tribalbc

Posted July 24, 2009 - 06:33 AM

#10

I have heard various things... some people have said the best gains are achieved by a more aggressive int cam only + hi-comp piston.




I'm thinking of doing this mod this winter when I refresh my motor. Any idea on what year YZ int cam works best ?
I would love more torque down low to mid, just don't want to lose that linear power. Not looking for a big hit, it would wear me out too much in the woods :worthy:
How was your 07 with both YZ cams ? Big hit anywhere, or just stronger everywhere ?

  • SJMC_DON

Posted July 24, 2009 - 07:55 AM

#11

I'm thinking of doing this mod this winter when I refresh my motor. Any idea on what year YZ int cam works best ?
I would love more torque down low to mid, just don't want to lose that linear power. Not looking for a big hit, it would wear me out too much in the woods :worthy:
How was your 07 with both YZ cams ? Big hit anywhere, or just stronger everywhere ?


06' is what I was told by a local motor builder here... both cams gave me what you had described more torque down low... not a hit but a tractor like pull that you would see with a long stroke motor. Stronger pull in the mid, it seems as if the gears get taller...

Did you do that Nickel (Plate?) enduro at Apex? I was supposed to be there but had to bail at the last minute... my buddies went up and did pretty well.

  • tribalbc

Posted July 24, 2009 - 09:30 AM

#12

06' is what I was told by a local motor builder here... both cams gave me what you had described more torque down low... not a hit but a tractor like pull that you would see with a long stroke motor. Stronger pull in the mid, it seems as if the gears get taller...

Did you do that Nickel (Plate?) enduro at Apex? I was supposed to be there but had to bail at the last minute... my buddies went up and did pretty well.



Sounds good, I think I might try that this winter. My only worry is the HC piston and pump gas. If I'm gonna need race gas I might just try the intake cam change.

Yeah I was at the Nickel Plate, it was a blast.
I ended up tipping a few beers back with your fellow stumpjumpers on Sunday night :worthy:

  • superbad

Posted August 05, 2009 - 04:24 PM

#13

I just finished doing both hotcams in my 07 WR450 along with a port/polish on the head, forged JE piston (stock compression) and added the mega bomb header to my powercore 4. My jetting is off pretty bad in the mid range (AIS kit) but it pulls very strong up top. I dyno'ed at 46.5 hp before all the mods so we'll see what I get when its running right. I have a JD kit sitting here which is probably what I am going to try to work with. Does anyone know the difference between the YZ and WR JD kit? Im thinking I should probably have the YZ since I basically have one now...

P.S. this is all setup for street riding (supermoto). Best bike ever to convert over!

  • CanadianWR450

Posted August 06, 2009 - 02:01 AM

#14

The only difference in the JD kit instructions for my 04 was the needle clip position. The YZ had it one clip richer then the WR.
It is the same kit for both bikes, and comes with instructions for both




 
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