07 yz250f

well im going to pick up a brand new 07 yz250f. 5100 otd. pretty good price id say. but i have a few questions on how you guys brake in the motors. i no some people that dont even brake them in they jus ride and then rebuild the motors. but this bike is going to be stock for a while until i sell one of my other bikes. so i was wondering how you guys brake them in. i have broken in other bikes but im not sure if i should do it the same way as this.:excuseme: . so how do you guys break them in? thanks.

For WR's only:

Do the grey wire and sky blue wire mods, AIS mod, install the YZ throttle stop, remove the exhaust insert. Drill out the fuelscrew cap and adjust the pilot circuit. If you don't do these things, especially the grey wire and throttle stop, you can't load the engine as well. The sky blue wire mod is supposed to help with setting your pilot circuit properly by providing normal spark energy in neutral.

Break-in (WRs and YZs):

Heat cycle it twice on a stand. Run it enough to get the engine good and hot without boiling over. This knocks off most of the larger metal particles, burnishes journal bearings, and seasons the piston, rings, pin, and rod before they're loaded.

Ride it hard for 10 hours, especially the first hour. Vary engine speed and load a lot. Don't get too extreme with it. Keep it off the limiter. Get the main and needle circuits setup during this time. This mates the rings to the cylinder and burnishes in the transmission parts.

Do the post break-in maintenance exactly per the manual. Change to a synthetic oil.

Make sure *any* warranty issues are addressed within 30 days.

I'm a big fan of motoman. :thumbsup:

where can i buy those mods? and how much will they cost?

For WRs:

They're free, except for the AIS and YZ throttle stop.

The TT store has the TT AIS mod and throttle stop.

Your local Yamaha dealer has the GYTR AIS kit, which includes the throttle stop. The TT store might also be able to get the GYTR kit at a good price. I'd give them a call anyway.

Most of the free mods are here:


For the '07 exhaust insert, drill or grind off the rivets that hold in the exhaust insert. Bang out and/or pull on the insert until it comes out.

Alternatively, the GYTR 96dB spark arrestor ($45) can be used instead of the tiny 82dB one.

The grey wire is located by the ECU behind the while panel to the rear of the airbox door. Pull the pin from the connector and tape it with electrical tape, or cut the wire and tape the ends.

The sky blue wire is located in a connector under the gas tank towards the front. Disconnect the connector and tape the ends. This mod requires holding the clutch to start the bike in neutral (like a YZ).

You can cut the factory WR throttle stop to the YZ length, but the GYTR kit includes the correct throttle stop, a better needle, and a leak jet to help get rid of the off-throttle bog that you might have.

Once you drill out the fuelscrew washer, you can adjust the pilot circuit here:


If the bike runs right, you can break it in without making this adjustment.

You don't need to do all (or any) of the mods before breaking in the bike. Doing them will allow you to seat the rings a bit more firmly while making the bike perform quite a bit better than "as delivered". Most importantly, enjoy your new WR! :D

are you getting a yzf or a wrf? if its a yzf there are no mods, they are already done. the yz motor is already opened up, the wr is not.

im still trying to brake mine in, 10 hours is alot of time on a track.

im getting the yz, and yes 10 hours is a while. so i should ride my bike hard for 10 hours and then how ever i want after that?

im getting the yz, and yes 10 hours is a while. so i should ride my bike hard for 10 hours and then how ever i want after that?

Gah, I can't believe I misread the bike. Thanks for catching that, Ohio_k5. I modified my previous posts. :bonk:

Mostly, you want high cylinder pressures for the first 30mins to an hour after you've heat-cycled it.

Since the bike is warranted for the first 30 days, if something is going to break on a new bike, it's best that it happens early so it doesn't come out of your pocket later. I don't mean beating the bike to death, but babying them when new seems to delay warrantable failures (imo). The dealers bitch about it regardless. :banghead:

i heard that all i need to do is warm it up real good, baby it for 10 mins, then run it hard for 5mins, then let it sit and change the oil and air filter. then keep doing that.

manual says 1 hour continous riding 1/4-1/2 throttle.. thats what my son did then nest day about three hours of track time .. manual said after 1 hour its ready to race.

That will get you a low(er) compression bike (according to motoman), but nothing will break.

the manual doesnt suggest the best way. moto man's way is the ticket. take it through all the ranges and dont keep it pinned for to long. and DONT do it in ur garage. u need coolage and a little load on the bike to do this properly.

have fun with ur new bike. :D :D :D :D :banana:

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