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WR450 De-Restriction and Conversion to YZ Spec Street Legal Machine

341K views 492 replies 77 participants last post by  dave ls1 
#1 · (Edited)
I recently purchased another '09 WR450 and it came completely corked up as they do from the factory. Regardless if you have a '98 WR400 or a brand new '12 fuel injected WR450, this thread will provide some helpful insight on what to do to get your machine to how it should have come from the dealership (minus the carb and jetting for the fuel injected bike(s) :lol:). I also thought that I would cover what is required to get to a "street legal" status...or pretty close anyway due to differences in laws between states. Hopefully this will shed some light on just how easy it is to get one legal and running like a true 450. I will also provide part numbers where I can. Keep in mind that these bikes are street legal machines in various other parts of the world, so most of the components and the wire harness are already set up to adapt the bike for street use and makes for a simple low cost conversion. I will also cover some other things like tire/rim sizes and chain blocks. I'm still building the bike, so this thread will be a work in progress for the next few days or so.

So to get started, here's the bike:







First things first, as soon as I got it home and out of the back of the truck I began disassembling since the bike was so choked up that it wouldn't get out of its own way.









As with any new bike, one thing that gets overlooked is the steering head bearings and the swingarm linkage. They do NOT come adequately greased, if at all, from the factory. So the first item was to break out the tub of grease and drop the forks, rear shock, and swing arm.



While I was tearing the bike down, I went ahead and removed the AIS pump and lines and installed the AIS block off plate. At this point, if you have an aluminum framed bike and are going to install a horn, the former AIS pump location is a great place to mount the horn.





After some scrubbing with a scotchbrite pad and WD40, it was time to re-assemble some of the bike:



Since I was working on the handlebars, I went ahead and installed my headlight switch:



Here's the part number and information on the headlight switch. I'm not too worried about a horn or turn signals on this bike, so a hi/low beam and kill switch is all that I am concerned with. This switch is plain, simple, and has a clean look to it:



I also installed the hydraulic brake switch:



When I get the bike the rest of the way together I plan on installing hand guards. This is why I chose to go with the "low profile" switch. It costs a little more, but also makes things a lot more simple when clearance becomes an issue.



I will also be installing a keyed ignition which I will get to later once the mail man brings it by.

So now it's time to get to the heart of the bike and what makes or breaks it...the carburetor.





The steel frame bikes offer easy access to the carb which makes jetting an easy affair. However, with the aluminum frame you have to tear half the bike apart to gain access. That being said I was reluctant to use the jets that came in the GYTR AIS kit since the main jet was a #175 which is a pretty rich main. Not wanting to have to do this twice I also ordered a JD Jetting kit as well...mosly for the needle. I will try to give a little bit of info. on why I chose the particular products that I am installing on my carb as I go along.

Included in the AIS removal kit is a shorter throttle stop. Since the cover was already off, I started with the throttle stop:



This is a picture just for a comparison:



The next step is to remove the float bowl. Once that is done, the fuel advance rod will need to be removed. I didn't take a picture of it, but it connects to the black plastic arm in the upper part of the carb by the throttle stop area and runs through the carb body down to the fuel advance side of the float bowl. You'll need a pair of basic pliers and simply pull it straight down to remove it.

Now since one of the big short comings of the FCR carb is the dreaded bog, there is a simple solution/fix to it made by R&D Racing. The name of it is the Power Pump and it is basically an adjustable leak jet. You also get another vital component to make the carb run correctly, which is a stiffer fuel advance spring. Since I was working on this part of the carb, I went ahead and installed the spring:







Now it's time to install some more appropriately sized jets. The JD kit comes with relatively detailed instructions. In my case I have just figured out which jets work best for me through lots of trial and error, blood, sweat and a lot of foul language. My elevation is about 600' so I went with a #50 pilot jet and a #170 main. Here are the respective locations of the jets:



While you're this far into the carb, it's definitely a great idea to check your float height. Per the manual, it calls for 8mm from the bottom of the carb body to the top of the float. Once again this is just some simple insurance for peace of mind:

(note that the camera angle makes the picture/float height look kinda off)


With that out of the way it's time to address the float bowl. Now the purpose of the circuit in the float bowl is to feed fuel to the fuel advance. Fuel is pulled through a check valve and is pressurized by the diaphragm which is activated by the arm which is connected to the throttle turnbuckle. Confused yet? The other part of this system is the leak jet. Now in most cases a bigger jet number would be a larger size/more fuel. In this case, the leak jet allows some fuel to bleed back into the float bowl. This means that the smaller the leak jet number/size=more fuel being advanced. To dial in a leak jet you would normally have to pull the float bowl off to make an adjustment. With the R&D adjustable leak jet you can simply make any adjustments externally with a flat blade screwdriver.

For installation of the adjustable leak jet you will need a punch and a 2mm allen wrench.





Now flip the float bowl over, it's time to install the final piece. You will want to make sure that the diaphragm spring is on and that you install the o-ring (from the bottom housing that you removed to gain access to the diaphragm) in the new adjustable leak jet.





Now you're ready to button up the bottom end of the carb and off to the needle.



You'll remove the plug from the top of the carb slide assembly.

Remember this thing that you found in the tool kit that came with your bike (if you got a tool kit with your bike lol):


Well this is what it's for:




Place the clip on the recommended slot on the appropriate needle and re-install. I also bought a R&D flex jet screw. This gives easy access to the fuel screw and also prevents it from ever falling out.

 
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#81 ·
Wicked crash! How does it handle the dunes? Never rode with a paddle tire, but the 07 I just got last week, dude gave me extra rim with sprocket disk and paddle tire along with a bunch of other extra stuff. Bike only has 1000 miles on it, one owner.
 
#83 ·
Hey Crash,

Another question on hubs and wheels, might be helpful for others as well. If I run a set of rims without a Cush drive in the rear, do I really need to worry about my tranny getting worn out or damaging pretty quick? I thought I read somewhere that there are sprockets I can get that will help absorb the beating as they have a slight Cush in them or something like that but I can't seem to find it. I am really tempted to get the rad mfg rims but daaaamn that's steep for a rear rim. $870.

Thoughts?
 
#85 ·
I don't think that you'll have a problem if you run just regular hubs. That's all that I have run on all of mine and I haven't had any problems. However, the cush hub will be easier on the drivetrain and will also alleviate chain slap. Either way you go you'll be fine.


I run mine loose to compensate. But are you talking about something like this?
https://kushsprockets.3dcartstores.com/
Unfortunately those sprockets are no longer available.
 
#88 ·
Just chain slack wise. I could be wrong and I way through chain sliders a lil more.
 
#99 ·
Hey crash, a few questions about the quad masters cylinder. What banjo did you end up with ....stock quad one? Also what did you do with the lever? The stock fatwheeler lever that came with master is like 3 feet long lol. Btw mine came off a 06 yfz but I'm pretty sure its identical to the honda one.
 
#100 ·
I just used my stock lever and mounted it on the yfz master. I had to use the peice that actually pushes in on the master from the yfz and attached my stock short lever to it. If that makes sense
 
#103 ·
Thanks guys. I ended up figuring out that the wr lever fits on the quad "middle piece" and my master came with the banjo so that's good. My problem now is that the Phillips heads are stripped on the resivior. I'm going to the H.F. to look for one of those screw drivers that you whack to turn. Hopefully it works!
 
#105 ·
If those stripped screws are philips head I've had good luck hitting the center of the "X" with a ball peen hammer. This does two things for you. First it mashes the cross slot over and then I take a tight fitting screwdriver and hammer it in to reshape slots in the head. The other thing it does is the hammering shock loads the threads and can sometimes help break a stuck screw loose. Once I get the screws out, I always replace them with new ones. If you have to do that procedure just once, you won't want to ever have to do it again.
 
#106 ·
Possible dumb questions:

When I get my YZ exhaust cam, what do the stages mean? I assume a stage 1 exhaust cam will work?
 
#108 ·
I converted another WR450 yesterday. He was sent the Quickshot 3 by mistake, but we decided to use it anyway. I'm not thoroughly impressed by it yet, but once I get it dialed in I'll report my results. First and foremost it doesn't come with the AP spring which is vital to eliminating the "bog". Not to worry, I had a new one in my spare parts lol...

 
#219 · (Edited)
2009 WR450F carby woes





G'day Crash,

I've recently purchased a 2009 model WR 450 with only 700kms on the clock and really love it - except for the off idle bog which I just can't get rid of and which has caused me to stall the bike (and drop it!) on way too many occasions. By bog I mean that if I crack the throttle fast the bike either hesitates and nearly stalls, or just cuts out altogether. On a separate note, the bike also gets hard to start when the bike is hot.

Standard, the Australian version of the bike is way too lean because of the road regulations but that is remedied by way of fitting the additional carby kit that comes from Yamaha with the bike when purchased new. I'm guessing these carby parts form the GYTR carby kit, but I could be wrong. Anyway, I fitted the kit and the bike felt way better for it - except the bog was still there at all altitudes I ride the bike - from 0 to about 800 metres.

I then found your excellent post on this problem and ordered the stiffer Merge Racing pump spring, and the R&D adjustable leak jet from ATV Unlimited. However, they sent the Boysen Quickshot 3 adjustable leak jet instead so I had to fit that (apparently the R&D one is not made any more????). After refitting the carb with the new bits but before fitting the airbox etc I played with the leak jet adjuster and saw that indeed the duration of the squirt varied in each different position, so knew it was doing its job. However, when I got the bike back together and went for a ride, no matter how I adjusted the leak jet screw in quarter turn intervals from fully closed to fully open, the bog was still there. So I just can't work out what's wrong with the bike or why the adjustable leak jet and stiffer spring doesn't fix the problem when it seems to be successful on so many other people's bikes.

Currently the bike is set up as follows:

Air box opened up;
TPS still connected;
Grey wire mod NOT done;
XCR Vance & Hines muffler;
AIS not fitted to OZ model;
Shorter throttle stop;
R&D stiffer AP spring;
AP timing screw standard position (squirt misses slide);
Correct float height;
Main jet - 170 (175 came in the Yamaha kit but I thought it would be too big);
Main air jet - 110 (as supplied in the Yamaha carby kit);
Needle - DSQ-3 (I don?t know what these numbers mean but it came in the Yamaha carby kit);
Needle clip position - 3rd (as recommended in the Yamaha carby kit instructions);
Pilot jet ? 50 (as supplied in the Yamaha carby kit);
Pilot screw ? 2 turns out (as recommended in the Yamaha carby kit instructions);
Leak jet - the Yamaha kit came with a 45. I fitted this but still had the bog, so that's why I've now got the Quickshot 3 adjustable one fitted;
All other jets are standard.

I saw a post made by yourself In March this year where you did the carby on a mate's bike using the Quickshot 3 and a stiffer AP spring etc. In that post you say you would post the results with the Quickshot 3 fitted but Ive searched for the post and can't find it.

My first question now I guess is how did you go with setting up the carb with the Quickshot 3? Was it successful, and what were the final set up specs etc?

And my second question would have to be, what am I doing wrong? What have I missed and what should I do that I haven't already etc?

I've only ridden the bike 6 times but have already had the carb off 3 times to try and get it to run properly - not a very good ratio!

Any help (and valium) you can send me will be very very much appreciated Crash.

Thanks heaps,
Greg
 
#109 ·
Jeff, ive been meaning to ask you this for a while but havent gotten around to it. Is there a way to dial in the carb on a budget? Ive been looking at the power bowl and all the parts you mentioned and they seem to be a little pricey. I have the AIS removal kit but im wondering what else i can buy somewhat inexpensively to get the bike completely dialed in. Thanks!
 
#111 ·
Hey Crash, I tried to PM you but apparently you are a busy guy because your inbox is full. I will post it here in hopes you see it. I know you are the WR guru of this forum. I have an odd front wheel problem that I just cannot seem to figure out. The front hub is what I believe to be an 03 WR hub. I am guessing this based on the fact that the hub has 4 ribs on it and a WR like speedometer drive. The hub is laced to 17" excel rims which I am trying to mount to my 2007 WR450. The problem I am having is the earlier hub is much more narrow than my 07 hub. It is approximately an 1.3 inches more narrow. I have tried to make it work with either 07 spacers, and i even purchased an 03 spacer and a speedometer delete spacer from flatland racing. I have tried this setup with both my stock brakes and my radial mount brembo setup, but there is a ton of slop either way. Any help you could contribute would be much appreciated. Thanks man.
 
#114 ·
haha dick ^ Thanks for the response Crash, I actually figured out apparently I was not pushing the axle far enough into the fork. I don't remember being able to do that on the old KTM and somehow Sourdiesel and I missed it. Then again, it could have been the beers :cheers:
 
#122 ·
the bike runs well considering its so corked up! But i do have one question.... I think its probably normal but i havent had a cable clutch in a long time, or a yamaha. The clutch is quite noisy when the bike is in neutral and clutch out, also when the bike is in 1st gear, bike stationary and you feed the clutch out without touching the throttle at the point just before the bike starts moving you can feel a strong pulsing coming from the clutch, can feel this through the whole bike also? Just wondering if this is a normal WR thing or if i should look at the clutch? Thanks
 
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