How difficult is the "cam swap"


21 replies to this topic
  • john.hilton@cape.k12.de.u

Posted March 06, 2006 - 06:09 AM

#1

Hi, I've been out of the bike loop for over 2 years since having kids, but I have a quick question.

I have an 01' YZ 426 and I've been thinking about swapping the exhaust cam for the 03' 450 so I can have the auto de-compression.

Has anyone done this mod ???

How much does the new cam cost ???

How difficult is the swap, is it something I can do, do I need any strange tools ???

Is there any difference in the way the bike will run with the different cam ??

Thank you VERY much for your help. :thumbsup:
John

  • dsconstructs

Posted March 06, 2006 - 07:23 AM

#2

I recently did this. Need in/ft torque wrench, basic metric tools, feeler gauges for valve adjust and a manual sure came in handy. There are excellent instructions in here for doing it that made it pretty simple really so you can be sure to time it correctly.
I'm still waiting to test ride it more than up and down my street, but to me it smoothed the bikes power out besides the other obvious benefits. I'd do it again in a heartbeat. The TT store has the cam for about $100, plus a few other places on the internet....the dealer wanted $150. I used honda valve shims instead of driving out of town to the nearest Yami dealer when it came time to adjust the valves.

  • Raven1911

Posted March 06, 2006 - 10:19 AM

#3

All the information you want is in the YZ450 cam thread at the top of the page. Go there and you can get some information. I have yet to do it on mine as well but am seriously thinking about it! Haven't heard one thing bad about it. PM me your email address and I will send you the attachments for the instructions on from the forum. Really nice pictures and everything.

  • 642MX

Posted March 06, 2006 - 10:29 AM

#4

There is a thread at the top of the page with all the info about the swap.

  • grayracer513

Posted March 06, 2006 - 10:44 AM

#5

It's about as simple as a thing gets. There is only one caveat: the timing marks on the cam intended originally for the 450 do not line up in the same way as the stock one does. The cams need to be timed by first getting the intake right, and timing the exhaust off of that.

If there is no reason to remove the intake cam, such as to adjust the valves, zip-tie the cam chain to the intake sprocket, and then time the exhaust to the intake as you go together with it.

Using the "12:00 o'clock" marks on the two sprockets, count 14 pins between the marks, and you're good. Here's a link to an instruction sheet, which has a picture of how it should set up:

http://www.thumperta...078#post3706078

This mod is, without question, the best thing you can do to the bike. I come from an old school thumper background, and was already very familiar with manual compression releases, and all of the things that can be done with them. I was skeptical enough of auto decompression that I considered not buying a 450 unless I knew I could convert back to manual. Not anymore. Simply put, there is no downside.

  • cowboyona426

Posted March 06, 2006 - 11:40 AM

#6

It's cake, you'll be glad you did it when you're done. I can point you to a pretty thorough post at another site if you need more details on how to do it etc.

  • RD73

Posted March 06, 2006 - 02:06 PM

#7

It is not difficult. In fact, if you've ever checked the valves before, it will be a breeze.

Regarding whether others have done the cam swap, yes. It is an extremely popular mod for the 426. When I was calling dealers checking pricing for the cam, I also asked them how many 450 cams they sold last year. Every dealer had sold several.

  • kid on a 426

Posted March 06, 2006 - 04:18 PM

#8

Well unless you need to start the bike in a hurry for some reason i dont see the point in one (no offense). It does smooth out the power but I personally love the snap, I like the manual decompression it makes it easier for me to start for some reason. It helps me start it the first kick because it forces me to line up and get the kickstarter all ready.

  • Dolce_Grappa

Posted March 06, 2006 - 05:01 PM

#9

Get yourself a HotCam. No funky offsets, a little more lift and duration giving gains towards the mid-top w/ little loss down low. Either way you'll love the change!

  • john.hilton@cape.k12.de.u

Posted March 06, 2006 - 05:10 PM

#10

Thanks for the advice! I'm not totally sure I want to do it but I'm trying to get some information.

The next to the last post says a lot, I don't really need to start the bike quickly any more. I used to race Hare Scrambles before I had kids, and now my wife won't let me race, :thumbsup: so I'm really just trail riding.

About the Hot Cams product,

1: Can you buy those at the TT store ??

2: Do they take away from the low end ??

3: Are there any problems with them shortening the life of your top end, i.e. valve train, not piston and rings?

Thanks again for the information.
John

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • grayracer513

Posted March 06, 2006 - 06:04 PM

#11

Well unless you need to start the bike in a hurry for some reason i dont see the point in one (no offense). It does smooth out the power but I personally love the snap, I like the manual decompression it makes it easier for me to start for some reason. It helps me start it the first kick because it forces me to line up and get the kickstarter all ready.

Unless you see the need to confine yourself to a rigidly outlined regimen for starting your bike, and being unable to "just crank it", and you see some reason why a bike that bump starts like a 125 is a disadvantage, and you see no benefit in a bike that can be restarted after a brake stall with a simple flip of the clutch (or just letting off the brake) then I see no reason for you to suggest that there's no point in the mod. Trust me, there is nothing about the manual decompression setup that makes anything any easier.

There is also nothing about the use of an OEM 450 cam that reduces any of the "snap". It simply makes it available across a wider range.

  • cowboyona426

Posted March 06, 2006 - 07:26 PM

#12

Well unless you need to start the bike in a hurry for some reason i dont see the point in one (no offense). It does smooth out the power but I personally love the snap, I like the manual decompression it makes it easier for me to start for some reason. It helps me start it the first kick because it forces me to line up and get the kickstarter all ready.


It's funny how everyone who HASN'T done the mod has the same excuses as to why not to do it... :thumbsup:
Don't waste your money on a Hot Cam, get the OEM cam. It makes the power much broader, makes starting a no brainer, and is hands down the best $ you can spend on a 426. Don't believe me? Read the thread at the top of the forum and ask everyone else who has done it if it was worth it.

  • 642MX

Posted March 06, 2006 - 08:54 PM

#13

Its one of the best things you can do for a 426. I run the Hot Cams, it has no effect on cam chain, piston, valve or valve spring life. The hot cams add power everywhere, it takes nothing away from the hit or snap. I'm sure the TT store carries Hot Cams. Don't forget to get the TT decompression plug also. You can take the actuator out of the cylinder head and replace it with this anodized plug (comes with a new seal too).

  • srhines67

Posted August 24, 2006 - 10:49 PM

#14

Its one of the best things you can do for a 426. I run the Hot Cams, it has no effect on cam chain, piston, valve or valve spring life. The hot cams add power everywhere, it takes nothing away from the hit or snap. I'm sure the TT store carries Hot Cams. Don't forget to get the TT decompression plug also. You can take the actuator out of the cylinder head and replace it with this anodized plug (comes with a new seal too).


Are you running both cams or just the exhaust. I just have the exhaust cam and my bike seems a little slower. The folks at hotcams said that they went more for mid and top end if you install both of their cams.

  • 642MX

Posted August 25, 2006 - 09:20 AM

#15

Are you running both cams or just the exhaust. I just have the exhaust cam and my bike seems a little slower. The folks at hotcams said that they went more for mid and top end if you install both of their cams.




I use both. :thumbsup:

  • srhines67

Posted August 25, 2006 - 09:28 AM

#16

Did you loose any bottom end?

  • 642MX

Posted August 25, 2006 - 09:30 AM

#17

Did you loose any bottom end?



Nope. As a matter of fact, it gained power everywhere.

  • mike_dean

Posted August 25, 2006 - 10:09 AM

#18

I'm using just the exhaust Hot Cam in my '00 426, and did not notice any difference in the performance, but starts very nice. Mike

  • srhines67

Posted August 25, 2006 - 10:32 AM

#19

I just talked to Hotcams and they have dyno tested the 426 exhaust cam only with the stock intake cam. There is absolutely no difference in overall power according to them. However, the power curve could have changed. They are going to call me back and give me the info on that. With both cams they predict a 9% increase in power.

  • bustersat

Posted December 08, 2006 - 07:11 PM

#20

All the information you want is in the YZ450 cam thread at the top of the page. Go there and you can get some information. I have yet to do it on mine as well but am seriously thinking about it! Haven't heard one thing bad about it. PM me your email address and I will send you the attachments for the instructions on from the forum. Really nice pictures and everything.

I was just wondering if you coulod give me all the info on the swap for a 2002 426. Mine runs sweet right now but would love to get rid of the decomp lever!
Thanks!
Shawn





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