I got a few general questions! PLZ read..

Hey guys, like I have mentioned in my other post i'm getting a wr450f... Well i'll be getting it from Japan as that is the closest country that people bring bikes down from.. My questions are, what are the differences from the Japanese model to the US model? I love the US model Wr so, I would make it like the US Model.. I think all I gotta do is;

Remove Side Mirrors

Remove Signal Lights

Remove The Number Plate Bracket

And remove the two reflctors on the two forks?

Am I right?

Also do the free mods apply to the Japanese model or just the US model?

Another thing is, on many threads I'v seen people say that they have a jetting kit on the bike or in they'r signature they say that they have a jetting kit on the bike.. What I understand is that jetting kits are needed only when the bike isnt running well right? Its an adjustment or an add on?

And also some guys say that jetting has to be done in trail riding? Isnt jetting a time consuming proccess? You have to take the carb out to rejet a bike right?

Also why is jetting needed? Why cant the neccassary adjustments be done with the air screw and the fuel screw?

Sorry if thid thread looked like a exam paper lol..

Please help me as much as possible thanks,


Jap model won't be ADR'ed, just like US model.

Jetting kits are an easy way to buy a few needles and some jets, required for better performance. If You want optimal performance, then a jet kit is highly recommended.

Jetting does require you to get at the carby, but with the benefit from others, you have got a great database of jetting settings to start with. Should be pretty much spot on first go!

Jetting is required once you uncork your bike. the fuel screw cannot compensate for lean jetting.

Bottom line - get the bike and we will help you out as much as we posibally can! :thumbsup:

Ok cool thanks!

So you mean to say that the Japanese Model is identical to the US model? If so SWEEET!

And also Jetting kits are an add on?

The jetting kit wouldnt add performance right? It would just give the bike tuning required to run like its supposed to?

Thanks ALOT,




Can you link us to the Japanese model so we can see what it looks like and what the features are?:thumbsup:

Uhh actually I got soo many questions because even I havent seen the Jap Model Yet lol..

Right now my question is, if I add a exhaust system on my bike, will I be able to tune the bike for the new exhaust through the Fuel Screw? If not what is the fuel screw for?

I think I understand what jetting does...

On the Fuel Screw FAQ, they say to check the fuel screw every race day.. My main concern right now is that more than riding the bike and having fun I will have to play with the carb??

And also the guy who imports the bikes is going to Japan on Wednesday or Thursday next week.. So basically I would have a Wr450F 2007 Model abit used or a 2008 Wr450F brand new.. If the price is ok for the brand new of course thats gonna be the go!!

I DO PRAY lol!!



I would definitely re-jet. I did all of the free mods to my '05. Then I removed the AIS with the kit from TT in hopes of eliminating the pop on decceleration which helped a little bit. I decided to re-jet with the JD jet kit and used the jetting database as a starting point. According to the database I only had to change the pilot jet for the altitude and temperature I ride in. I replaced the fuel screw and installed the needle that comes with the JD jet kit. I didn't think I would notice much difference but was happy with the fact that the bike would last longer if it was running properly. The first time I got on the bike, there was a very noticeable difference in throttle response and how the bike pulled. I would definitely recommend changing the phillips head screws used on the float bowl and rear airboot clamp with allen screws. The screws were very tight on my bike and I ended up stripping a few of them.:thumbsup: The new allen screws make life much easier.

Oh ok cool thanks man! Keep the responses coming!

The fuel screw allows you to fine tune the pilot circuit which controls how the bike runs at the zero - 1/4 throttle opening, however, if you have the wrong pilot jet installed then adjusting the fuel screw will not do very much for you.

I'm guessing that it is not easy to find Keihin jets in Sri Lanka so I would order the JD jet kit so that you can make any changes that are necessary.

Yup thats exactly what Im gonna do.. Order a JD jet kit and a White Brothers XCR exhaust :thumbsup:

Now this stuff is starting to make sense to me, thank you sooo much guys!!!

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now