2007 WR450 Performance Mods

That lip is to hold the screw in case it vibrates out. Now that you added some weight and length to the fuel screw it would be a good idea to stretch the spring a tiny bit in order to give the screw a tighter fit. This happened to my 426 and stretching the spring did the trick.

Wrong kit! The ones for the '05/'06 won't fit the '07...SC

I just got the 07 WR 450 and it's my first 4 stroke. What are the mods needed asap? It feels pretty plugged up for a 450.

Yamaha should have AIS kit out in Jan. Until then, you can cut down the throttle screw or get a YZ screw. Open up the exhaust. 48 or 50 pilot jet.

Oh and do a search.

well just got back from my first real ride on the bike 106 miles. It is a great bike it rips and top end is unreal. i have done all free mods. my only problem was i blew my fork seal.

I just got the 07 WR 450 and it's my first 4 stroke. What are the mods needed asap? It feels pretty plugged up for a 450.

Read the Newbie Sticky!!!!...SC

I have gotten the following done to the WR:

Carb screw shortened

Air box opened

Inner tube in exhaust removed

Grey wire disconnected.

I started after the jetting last night, I removed the rear subframe, exhaust, shock for access. This is not a two minute job. :lol: I have a JD kit and a fuel screw on the way, however I am not sure when it will get here. I am debating on putting this back together or just waiting for the kit. I have the 170 main and 48 pilot in.

Does anyone think the spark plug is changeable with the engine in the frame?

Is there a better way to access the carb as opposed to removing all of this hardware?

The vent on the starter, what is its purpose?

I need to lighten this bike for racing, any ideas?

Yes the engine is changeable with the engine in. You just have to remove the gas tank. I assume you have an 07 so removing the shock is the easiest way to work on the carb if you need to remove the bowl but you don't need to remove the subframe. The hose on the starter is the crank case breather.

Yes it is a 07, I just recieved the manual and plug wrench today. I didnt get it when I picked up the bike that is a long story. I was distracted with the other bikes being picked up. I am going to attempt to remove the plug tommorow. I am also removing the AIS I need to get some plugs.

When I bought my 07 I had the service department handle the AIS and jetting, 50 and a 170. The service guy said that he plugged up the hoses but did not remove it. Does that work? It still pops bad on decel, is that the air/fuel screw or is the AIS not blocked off? Any ideas?

I would try the fuel screw as long as everything is blocked off on the AIS..

When I bought my 07 I had the service department handle the AIS and jetting, 50 and a 170. The service guy said that he plugged up the hoses but did not remove it. Does that work? It still pops bad on decel, is that the air/fuel screw or is the AIS not blocked off? Any ideas?

That sounds like a half-ass job to me. If everything is blocked off then remove the two screws and get rid it. My guess is that it is still there because they they don't have an 07 kit and didn't have anything to block the exhaust port so they just blocked the hose connections. If the hoses are just laying there it is still going to suck air (dirty air).

There is a plug in the small hose, not the larger one by the header. I think I need to just pull it off and plug it up. The carb is drilled out to get to the air/fuels screw its almost impossible to adjust without rotating the carb, will a aftermarket $20 screw fit in there.

There is a plug in the small hose, not the larger one by the header. I think I need to just pull it off and plug it up. The carb is drilled out to get to the air/fuels screw its almost impossible to adjust without rotating the carb, will a aftermarket $20 screw fit in there.

Yes, or you can make one like on page 2

Will an 06 YZ450 aftermarket slip on exhaust fit for the 07 WR450? Will the full system fit as well? Also, will an 07 YZ450 fit and 07WR450? Any clues??? Thanks!

Has anyone looked hard at the radiators?

Is the cooling system identical to the YZ's? Those YZ Rads look way to small to keep this beast cool in the tight and technical that ride up here the PNW. They also look as if they would not hold up very well to an impact, side or front.

If they are the same as YZ rads does anyone know if Fluidyne has a set made up yet? (Yes, Clark I know I'll check the website:busted: ). How bout a good set of Guards yet, anyone if flatland, rooster or anyone else have a set yet?

Thanks guys! Hopefully by the time I get mine in March everything will be figured out for me:applause:

Will an 06 YZ450 aftermarket slip on exhaust fit for the 07 WR450? Will the full system fit as well? Also, will an 07 YZ450 fit and 07WR450? Any clues??? Thanks!

yes they will fit ,u just have to use the pipe donut off the inside of the 07 wr muffler.:lol:( the header on the wr is smaller )

The WR radiators are actually larger than the YZ. One or two extra cores I think. I don’t know of many radiators that do hold up well to impact but at least they have attempted to strengthen them with the built in braces.

I dont know about a slip-on but TT member Derwud2 installed a 2006/2007 YZ450F full DR.D exhaust system on his 2007 WR450. He said it fit better than the factory exhaust. I bought the same set-up for around $400. Unfortunately it is sitting in my garage waiting for the bike to arrive on the 18th.

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