New 04 WR450 ?'s

I just bought a new left over wr450 yesterday. I am new to posting here but not to reading and informing myself about my recent purchase on the wr. I credit my purchase to the info provided on this forum. Thanks for allowing me to sponge off you guys.

I just want to make sure of the free mods to do on the '04.

No AIS on the '04 right?

Remove snorkel right?

Add insert to exhaust (at least)?

Remove gray wire right?

JD jetting kit right?

Throttle stop right?

I have already looked at the jetting page. My question is that if you order from TT do you have to call and specify all the particulars or is it in a package. I think I remember reading that it comes with instructions also right?

I am looking for the minimum and least costly mods at this time. Looking to get gift certificates for christmas.

Yes you are on the right track for the mods,

Gray wire

uncork exhaust and recork with PMB insert or replace muffler with FMF choice.

Yamaha jets needed 48 pilot jet , 72 starter jet, #40 leak jet, 170 main jet, 04 stock needle in clip #4 is pretty good (option for JD jetting only if you like perfect jetting and rejetting for rides)

air box snorkel removed and punch a few 1" dia holes on the right side and place 1" dia foam covered plugs to allow more air flow.

YZ throttle stop

And if you really want to wake her up, an '03-'05 YZ cam :applause:

Also, don't forget to re-route your valve-cover breather hose to your airbox (lots of posts here about different ways to do this) if you will be doing much in the way of water crossings, and put some silicone underneath the top chain glide to protect against damage to the swing-arm caused by the chain slapping the plastic around. I also re-routed two of the carburetor vent hoses into the airbox (again, for water crossings to prevent the engine from stalling in deep water). There are good posts on this site to show you how to do all of this.

And slap a good skid plate on that puppy while it is still new. I waited until I had dinged up my frame on a rock before I wised up. :applause: A good skid plate will also better protect the oil-lines and water pump from rock damage.

Jet the bike to Indys specs... They're right on!!

Thanks guys.

I have got a GYTR skid plate coming, beakr.

Thanks for replying Indy, it sounds like everyone respects your knowledge about jetting and I will too.

This is the first time I have heard of rerouting breather hoses, I will check into it.

This is the first time I have heard of rerouting breather hoses, I will check into it.

It's not THAT big of a deal....

Just don't stall it and try to restart with the end of the hose submerged :applause:

If I had it to do over again, the first thing would be UNI-BIKER rad guards, before I bent my rads. By the way, the GYT-R skid plate kinda sucks. My buddy got one(maybe not even the same as yours), but he wishes he would have got the Utah Sport I ended up getting after I saw his GYT-R. I dont mean to be a downer, just thought you may want to know. The breather hose is pretty important, just ask my bro. He sucked a ton of water in his. Now all of our bikes have the re-route done. I too have benefitted greatly from the knowledge on this forum, its a god-send.

I definately will be getting radiator guards very soon. Very nervous about that, since my last bike was air cooled xr 600, no rads to worry about.

I got the the skid plate for free along with a magnetic drain plug from GYTR cash back incentive. So hopefully it is a good free skid plate.

Indy, Am I understanding you correctly that the JD kit is not necessary. I will be riding at altitudes of 0 to 5000 feet. The list you gave me is the all around fix?

You can use a 170 main, 04 stock needle in clip #4 , a 72 starter jet, and a 48 pilot with an adjustable fuel screw for minor weather adjustments and never rejet it is a good all around setting for guys that dont like to rejet all the time. If you want the best performance go with the JD kit and you can find jetting recommendations on the pinned post on this forum. :applause:

I bought my WR 450 used. How do I know if I have the mods done or not?

thanks Indy

I bought my WR 450 used. How do I know if I have the mods done or not?

1 - Remove the air filter and using an inspection mirror, look down the carb throat with a flashlight. Have someone crank the throttle wide open. If the slide completely goes into the top of the bore, the throttle stop mod has been done.

2 - Before you put the airbox cover back on, look toward the back and top of the box. Is there a rectangular plastic tube feeding the box or is there just a large hole open to the seat? If just a large hole, the intake snorkel has been removed. Look at the opposite side of the airbox... are there any holes cut into it? If so, it has been "YZ'd"

3 - Remove the fuel tank and locate the electrical harness running south from the CDI module. There is a grey wire in the connector. If it is cut and taped or pulled out of the connector, the grey wire mod is done.

4 - Look at the end of the muffler. Is the opening barely big enough to get your finger into or is it bigger? If it's bigger, the exhaust has been uncorked.

Those are the 4 basic free mods, and the most effective things to do. Without these mods, all of the exhaust or cams in the world will not make it anything more than a WR300.

Next step to spend a few bucks is to install a YZ cam. This is tricky to tell if it has already been done or not, as I can't find any part numbers actually ON the camshaft. The only way to tell is to look at how long the autodecomp nipple is. The nipple on the YZ cam is about 2-3mm shorter than the WR nipple. Side by side, it's obvious... the YZ nipple begins it's curvature almost flush with the cam casting, the WR has a straight area before the curve starts.

If you have the WR cam, count the number of pins between timing marks (it's 13 on the WR250) and install the YZ cam with the SAME NUMBER of pins between marks... the YZ cam is indexed to retard the cam by one tooth compared to the WR, so the marks line up the same.

Thanks wheels I appreciate your time!

No prob.

What does replacing the leak jet and starter jet do? Is it important? Bought main and pilot and I am fixin to replace.

Local dealer did not know what these jets were. Should they have them in stock?

Dealers know crap! Most of them don't even ride! :thumbsup:

72 or 70 starter are better for cold weather starting but if your bike starts OK with the choke you can avoid having to do it.

40 leak jet will give your crisper throttle response when snapping open the throttle from being shut. It is not necessary if you are satisifed with the throttle response. :thumbsup:

Here are the part numbers to give your dealer if you want to order them:

Starter Jets:

3TJ-1494F-15-00 .JET (#70) AP 1

3TJ-1494F-16-00 .JET (#72) STD 1

Leak jet:

4JT-1494F-03-00 .JET (#40) AP 1

Wow, quick response.

Thanks again Indy.

It does seem to start a little tough on those cold days, 4-5 kicks instead of 1. And the e-start seems to struggle even if it is warm.

I am not happy with the throttle response at all. Most of my riding will be between sea level and 5000ft.

Thanks again


One other thing is to get rid of the rubber plug Yamaha used to plug the hole for the manual decompession lever. You can either get the aluminum one that's listed in the TT store of you can do what I did and get a 18 mm expansion plug used for oil galleys in automotive engines.


Why? Could you explain.

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