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What should I do next on my wr250f?

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I have a 2007 wr250f with a yz250f back shock and titanium spring. I have a megabomb header and powercore muffler. I'm looking for more power. I'm a little sketchy about boring it out. What are some different things I can do to get a little more?

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Have you already opened up the airbox and re-jetted?

Also, cut the grey wire to change ignition timing?

You can try a different cam. Can pick up peak hp.

Can try a 269 big bore kit for high rev increase, or try 290 kit for more grunt.

If that's not enough, buy a 450.

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I have not done the air box. Im not sure that I want to be cutting it. Do I need a rejet since I changed my exhaust? I have never rejetted it. I also have not cut the gray wire. I do have a yz throttle stop.

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Do all of the free mods first including the YZ cam timing, air box and gray wire. After all that then you must re-jet. The WR comes lean from the factory. Re-jetting it after you got the exhaust is a must.

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Go for different cams before going to a larger bore. Lots of potential there with the standard 250cc engine. A higher compression piston is also a good mod. And, disable the air cut valve system to clean up the partial throttle response.

But... If you are still running with the gray wire connected and you're reasonably happy with it, chances are quite high that you're not looking for the kind of power that the engine is capable of. Not trying to be disrespectful here, just saying... Do the easy stuff first and then see how you like it.

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I have not done the air box. Im not sure that I want to be cutting it. Do I need a rejet since I changed my exhaust? I have never rejetted it. I also have not cut the gray wire. I do have a yz throttle stop.

There is no cutting involved to open up the '07 airbox. Under the seat behind the battery you will see the "snorkel" tubes on top of the air box. Remove the metal bracket and wiggle the snorkel out of the top of the air box. That as all there is to it.

The Grey wire mod is the other power increasing "free" mod you need to do. After all the free mods are done I highly recommend the JD Jetting jet kit. Ride the bike after doing all the free mods and see if you really need more out of the bike. My bet is...you won't.

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Go for different cams before going to a larger bore. Lots of potential there with the standard 250cc engine. A higher compression piston is also a good mod. And, disable the air cut valve system to clean up the partial throttle response.

But... If you are still running with the gray wire connected and you're reasonably happy with it, chances are quite high that you're not looking for the kind of power that the engine is capable of. Not trying to be disrespectful here, just saying... Do the easy stuff first and then see how you like it.

Regarding this statement, so, for an intermediate rider like myself who doesn't really like wide open 4th 5th gear pinned trails, and would most likely be doing tighter single track and/or atv width trails where id hit 3rd gear tops, should I also hold off on the grey wire? (2001 WR250F). Do the other mods first and try it. Which leads me to my next question. If I do all the mods besides the wire, and re-jet the bike to dial it in after all the mods are done....say im up north and I'm getting real used to the power and I almost feel like i wish it had more...could I then just cut the grey wire...or would I then have to mess with jetting again?

Also, I am planning on putting an 03 or newer cam combo in, just dont know which ones yet.

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Definitely do the gray wire, open the airbox, and re-jet. If you get a JD Jet kit, it gives you pretty precise instructions for the setup you have. You could also do some research and just buy the needles and jets that would work to save some $, but I liked the JD kit because of the instructions and variety of options. That will make a world of difference. Depending on what you're looking for, a simple change of gearing can change the "power" around. I dropped to 12 tooth front sprocket, and it's perfect for the rocky single track we ride...

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Regarding this statement, so, for an intermediate rider like myself who doesn't really like wide open 4th 5th gear pinned trails, and would most likely be doing tighter single track and/or atv width trails where id hit 3rd gear tops, should I also hold off on the grey wire? (2001 WR250F). Do the other mods first and try it. Which leads me to my next question. If I do all the mods besides the wire, and re-jet the bike to dial it in after all the mods are done....say im up north and I'm getting real used to the power and I almost feel like i wish it had more...could I then just cut the grey wire...or would I then have to mess with jetting again?

Also, I am planning on putting an 03 or newer cam combo in, just dont know which ones yet.

Before you mess with Cams etc I HIGHLY suggest doing all of the free mods. If you have not done so the next step I suggest is an aftermarket exhaust as the first place to spend $$. If after all of that you feel you want more out of the bike, look into Cams, Big Bore, etc.

I was worried on my '09 that doing the mods would turn the bike into an explosive bike that is not suited for single track and tight technical stuff. This is FAR from the truth. I did all the mods and an full FMF exhaust, JD jet kit. The bike is now totally awesome. It has as much power as I need and the power is completely controllable. You can chug it in the low gears in the tightest stuff, or open it up and upshift during hill climbs. I absolutely love it and feel no need for Cams etc. That being said the '07 and later bikes are quite improved from the earlier WR's so you may feel the need for spending $$$ but I suggest ALL the free mods first. You won't be sorry.

Oh...if you are concerned about the grey wire mod you should just unplug the wire instead of cutting it. That way if you don't like it you can plug it back in.

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Before you mess with Cams etc I HIGHLY suggest doing all of the free mods. If you have not done so the next step I suggest is an aftermarket exhaust as the first place to spend $$. If after all of that you feel you want more out of the bike, look into Cams, Big Bore, etc.

I was worried on my '09 that doing the mods would turn the bike into an explosive bike that is not suited for single track and tight technical stuff. This is FAR from the truth. I did all the mods and an full FMF exhaust, JD jet kit. The bike is now totally awesome. It has as much power as I need and the power is completely controllable. You can chug it in the low gears in the tightest stuff, or open it up and upshift during hill climbs. I absolutely love it and feel no need for Cams etc. That being said the '07 and later bikes are quite improved from the earlier WR's so you may feel the need for spending $$$ but I suggest ALL the free mods first. You won't be sorry.

Oh...if you are concerned about the grey wire mod you should just unplug the wire instead of cutting it. That way if you don't like it you can plug it back in.

Yea, but the '01 has manual decompression, if i switch to 03+ cams I can have automatic like the newer bikes and not have to deal with manual. Plus i wanna do a preventative cam chain during off season, so id be right in there. At that time Id do the YZ cam timing, IF thats a mod i should strongly consider?

By the way the bike does have a full Big Gun exhaust on it already far as the exhaust mod is concerned, anyhow, thanks for the reply!

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