| It's always fun to make your dirt bike more powerful | | | | retards the timing on the mid-to-top-end of the RPM |
| and go faster. But, it's difficult for many riders to | | | | range, thus making it a slower and more poky ride. To |
| choose what they want to buy for their bike because | | | | give it more power in the upper RPM range you simply |
| money is tight. If you own a Yamaha WR250F dirt | | | | have to get rid of the gray wire. You can either cut it, |
| bike though, then you're just in luck, because I would | | | | or take it off and cover it with some tape. |
| like to share a few mods that you can do to make it | | | | To get the the wire you have to take off the seat, the |
| faster. Oh, and did I mention, they're FREE! So if you | | | | tank, and the radiator shrouds. Find the CDI, which is a |
| want to get that extra kick out of your | | | | black box (on the right side of the steering stem for |
| almost-motocross-bike-but-still-a-trail-bike, then you're in | | | | '01-'02 models). There should be two different groups |
| the right spot. These modifications consist of altering | | | | of two wires coming out of the CDI. The kill switch has |
| the air-box, exhaust, CDI wires, and the throttle stop. | | | | a black wire and a black wire with a gray stripe. You |
| Air-box Mod | | | | want the other group with a black wire and a gray |
| The stock air-box on your WR250F dirt bike has a | | | | wire. It should be under the frame where the gas tank |
| snorkel/shield that helps protect the air filter from | | | | is. Then just unplug the connector and pull of the dust |
| water, sand, and other foreign materials. Although it is | | | | ring. Plug the connector back in and tape up the wire |
| safer on your filter, it also robs usable horsepower | | | | you just took off to the connector. Then you just slap |
| because it blocks air-flow. To change this you just | | | | the tank, shrouds, and gas tank back on and you're |
| unscrew it and pull the screen out. This mod will make | | | | good to go! |
| it more like the YZ250F because it doesn't have the | | | | Throttle Stop |
| screen in it. If you go out to the desert or a dusty track | | | | Who wants to be restricted, especially on a dirt bike?? |
| and want to protect the air filter, simply screw back in | | | | I know I don't, and that's why one of the first things I'd |
| the screen. Doing this will make more of a difference | | | | do on a WR250F is get rid of the ridiculous throttle |
| on the 2001 and 2002 models because the newer | | | | stop that limits it to 3/4 throttle. To get rid of this you |
| ones have a battery in the air-box that restrict air-flow. | | | | must go to the right side of the carburetor and take |
| Exhaust | | | | off the throttle cover that has a couple of allen bolts. |
| The exhaust baffle on the WR250F is very restrictive | | | | The throttle is a screw on the bottom of the throttle |
| because it has to be quieter and have a spark | | | | disk, as shown in the picture. To modify it to the length |
| arrestor for trail riding. The exhaust hole is very small, | | | | of the YZF throttle stop, take it out and cut it with a |
| taking away a lot of power from your dirt bike. To | | | | saw. The original size is in between 30 and 35mm, so |
| remove the baffle you must take off the ten-millimeter | | | | cut it to about 25mm. Put the throttle stop back in and |
| bolt on the end of the muffler that keeps it there. Then | | | | that's it. |
| just slide out the baffle and you will have instant power | | | | After you do these mods your bike will be about as |
| gains. Although doing this give the bike more power, it | | | | close to a YZF motocross bike as you can get. There |
| will be much louder, so keep that in mind if you ride | | | | are a couple more modifications you can do to your |
| close to crabby people that don't want people to have | | | | WR250F, but they require some special tools and a |
| fun these days. | | | | little extra cash. If you take out the exhaust baffle and |
| CDI Gray Wire | | | | decide that it's too loud where you ride, you can just |
| The gray wire on a WR250F from the CD ignition box | | | | get an exhaust insert for it that lowers the decibels |
| connects to the ground. The gray wire is what makes | | | | while still keeping most of the power. Good luck, and |
| the WR250F's timing differ from the YZ250F. It | | | | ride safe! |