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sxchamp03

2001 yz426 mods

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i just bought a used 2001 yz426 and was thinking about putting some new parts on it since its stock except for a new tire. Besides puttin on a new chain and fork seals on it i was thinking about putting the 03 decompression cam in and a new exhaust so i just wanted to know what success ppl had with other exhausts.

thanks, bryan

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why did u want to go wiht the auto decom. cam? i find it easier to start my 02' 426 with the decomp lever than it is to start my bros 02 CRF 450R with teh auto decom. cam(personal preferance i guess). i just bought mine and it came with a WB E-seris exhaust , new chain and gears, hand guards, and skid plate and the one that covers the waterpump. ive ridden it wiht teh stock pipe (acutally is a FMF Q pipe) and i runs alot better with the WB pipe. a guy recomend me to ge the Boysen Quickshot acceralator pump cover. also i have the ZipTye fuel mixture screw (highly recomend) to be honest the bike doesnt need to many extras, its def. a power house, maybe jsut a new set of tripple clamps and some bars and ur set.

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The single best mod you can do to that bike is to install an auto decomp. exhaust cam. Just the simple fact that you can kick it over quickly and easily is enough. But on top of that the bike will not be as likely to stall in tight woods or under hard braking into a corner...if it does it will usually compression start on it's own like a two stroke if you are still rolling. I went with the Hotcams exhaust cam and it brings up the low and mid-range power also.

The next best mod IMO is to get a new fuel screw (I use ZipTy) that you can adjust by hand. Once you have that dialed in correctly (easy to do) it will eliminate much of the zero to 1/4 throttle bog associated with that bike.

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I really like the way my stock camed 426 starts. It is super easy to find TDC as the kicker comes to a dead stop, pull the decompressor and move the kicker an inch, and now the motor is in a perfect place to start. One smooth kick and it comes to life with out a flinch. I started a couple of older bikes with the auto decompressor and didnt like the feel of it. Im gonna stay with the 2001 cam. You can jump start it also by pulling the comp lever and then release the clutch followed by the comp lever.

One kick, thats all it takes. :thumbsup:

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Get an auto decompression exhaust cam. Its the best thing you can do for $100. Another "must have" is a JD jet kit, the JD kit will clean up the jetting and will improve throttle response. For an exhaust, I use a FMF Powerbomb header and a Titanium 4 slip-on. :thumbsup:

If having a manual decompression cam was such a great feature, the 2007 YZ450's would have them.....but they don't. :lame:

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I really like the way my stock camed 426 starts. It is super easy to find TDC as the kicker comes to a dead stop, pull the decompressor and move the kicker an inch, and now the motor is in a perfect place to start. One smooth kick and it comes to life with out a flinch. I started a couple of older bikes with the auto decompressor and didnt like the feel of it. Im gonna stay with the 2001 cam. You can jump start it also by pulling the comp lever and then release the clutch followed by the comp lever.

One kick, thats all it takes. :thumbsup:

I have the stock cam also...My bike starts all the time..Never any problems..

I did do the bk mod..

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It's not a matter of whether it starts or not. My '02 started first or second kick every time with the manual decompression lever. I installed the Hotcams auto decomp cam and it still starts first or second kick...except now I just kick rather than go through the whole starting procedure drill. I can start my bike wearing flip flops...try that with the manual decompression lever. Plus I have stronger low and mid-range power.

You can find the Hotcams cam on ebay for around $145 and I have heard that you can get the oem '03 cam for $105. I went with the Hotcams as it was designed specifically for that bike whereas the '03 cam isn't.

Trust me (and 642mx)...it is the best mod you can do on that bike.

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I have tried a few different pipes on my 01, but I keep going back to the FMF Power Core 4, it seems to make improvements throughout the RPM range and has a spark arrestor for when I trail ride.

The hot cam is the way to go, it is slightly more expensive, but it is a direct replacement with the correct pitch on the sprocket.

Also do the mod to the accelerator pump, I would probably do that one first, that and correct jetting made the biggest improvement in my bike.

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Get an auto decompression exhaust cam. Its the best thing you can do for $100. Another "must have" is a JD jet kit, the JD kit will clean up the jetting and will improve throttle response. For an exhaust, I use a FMF Powerbomb header and a Titanium 4 slip-on. :thumbsup:

If having a manual decompression cam was such a great feature, the 2007 YZ450's would have them.....but they don't. :lame:

Yea Matt I hear ya...But... I still bet I can start my 426 with the decom level faster, better & more reliable than you can start yours with the Auto-Decomp! :p

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Yea Matt I hear ya...But... I still bet I can start my 426 with the decom level faster, better & more reliable than you can start yours with the Auto-Decomp! :bonk:

If you ever go riding with me again, you can show me.... :thumbsup::lame::p

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best mod is the 426 to 450 body conversion. IMO :thumbsup:

Im in the process of doing it now to my bike...

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I suppose if you spend the money, tear your motor apart, to install an auto decompresser, your gonna think its the greatest thing sense the mono shock.

"There is no way I spent all that money and labor with out getting the best mod ever, I even changed the oil!" "I know it started with one kick before, but it starts with one or two now, and I can do it with flip flops :thumbsup: "

You can start the manual decompresser with flip flops too. You can also move your 426 back wards about 12" after you shut down, now the piston is at tdc and ready for the one kick start with out having to strain your brain with the complicated starting ritual.

As far as performance gain, that would be null unless going to hot cams with a different performance cam, but stock or OEM you ain't gonna see it.

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with out having to strain your brain with the complicated starting ritual.

Strain your brain..?? Its so friggin easy, find tdc and kick..!! Thats the thing its difficult for some , for me its thoughtless..

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I suppose if you spend the money, tear your motor apart, to install an auto decompresser, your gonna think its the greatest thing sense the mono shock.

"There is no way I spent all that money and labor with out getting the best mod ever, I even changed the oil!" "I know it started with one kick before, but it starts with one or two now, and I can do it with flip flops :thumbsup: "

You can start the manual decompresser with flip flops too. You can also move your 426 back wards about 12" after you shut down, now the piston is at tdc and ready for the one kick start with out having to strain your brain with the complicated starting ritual.

As far as performance gain, that would be null unless going to hot cams with a different performance cam, but stock or OEM you ain't gonna see it.

Spend all that money and labor? Tear your motor apart? That's funny. Apparently you don't check or adjust your valves yourself or you would know that installing a cam is a breeze and requires less time and effort than a valve adjust...you should try pulling the valve cover off your bike, you would be amazed at it's simplicity. And like you say, there is a performance gain with the hotcam...I've heard that there is also with the oem cam but I can't speak firsthand on that.

I guess all the manufacturers are missing the boat by using auto decomp cams...

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The only people who have anything negative to say about auto decompression are the ones who don't have it.

I was raised on big British singles, among other things, and all of them had compression releases on them. I'm very comfortable with them, and I know and have used every trick there is to do with one. The first 426 I ever rode, I started first kick, first time on the bike. In fact, I almost didn't buy my '03 because it had AD on it.

However, having owned one, I don't see any reason whatsoever to want, need, or be bothered with manual decompression ever again. There is little or nothing of any importance you can do with a manual compression release that can't be done with AD. But the same can't be said in reverse. If you brake stall going into a corner with AD, a simple flip of the clutch will get you running again if you're even barely moving. And the bike bump starts like a 200cc two stroke.

I won't ever go back to manual by choice, and I know of no one else who will either.

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I love the debate over manual or auto decomp. Personally I am a fan of the manual because most of the kids I go riding with are two stroke riders and they have NO idea how to start my bike and im not about to show them. My cousin has a 01 426 with the hotcam in it. My 01 426 is bone stock other then a simple rejet. I prefer mine. Mine will start every time first kick. He has to kick a couple of times usually. And he has had his bike "borrowed" and the borrower coming off a rm 125 wasnt expecting the power and flipped it. Thats never happened to me. :thumbsup:

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manual decomp here too. but i put the msr clutch with the integrated hot start at the thumb. use the hot start for decomp. super ergonomic...and it comes second nature during starting. ive never thought..."wow, i hate using the manual decomp..."

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I still have the manual decompression lever on my 2000 YZ 426 and I would like to do the auto cam on mine. If I use the Hot Cams , do I need to re-shim my valves like I hear you have to do with the 03 stock exhaust cam?

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