CRF's Only Forums

Hello all,
I'm a 250X "convertee" I guess you could say? Back when I bought my 250X, riding trails and woods was all I had in mind... then I took a spin around an MX track and have loved it ever since. Since that day I have done as much as I can to the 250X to help it become more track worthy, and have reached a point where I (think) am 99% certain I'd like to move to the 250R (the major issues being the weight difference, proper suspension, and close-ratio transmission, all of which will help on the track).

Having changed so much on the 250X, I am curious if there are any 2007 250R owners that have found the need to do anything like rejet, install a Boyesen Accel. Pump, or change anything else on a bike which I hear is supposed to be pretty spot-on out of the crate.

I will probably end up transferring some things from my X over to the R (radiator guards, skid plate, etc) but was very curious what changes people have made to the 250R to get it to respond better than stock (if that's the right way to put it???).

Thanks in advance, guys. Very interested to hear what changes people have (had to/chosen to) make to their stock 250R.

I will miss the 250X, but it's a growth move
Have done a lot of work to that thing, and I think it just might be impossible to communicate to any potential buyer what a strongly, highly improved 250X they will be getting. Incidentally, if anyone knows of someone in the Tri-state area looking for a 250X almost-turned-R, let me know!
-matt

http://crfsonly.com/forum/garage.php?mode=view_gallery_item&type=garage_mod&image_id=1959

14 y/o son strictly races MX 07 250f (125 Junior)
(I'm assuming are not Int or Pro rider:)

The major problem we had was major bog, especially coming out of turn with motor loaded (sand)
MX requires a quicker throttle response, so this was a major issue. Had mechanic (Wrenches for local shop and runs support trailer at races) redo Carb.
He installed (TBT??) restricter ring which reduced carb to 38mm. 175 main 2nd from top. He also made accell pump mods (not sure what) and changed leak-down jet. Carb is 900% better. I had bought the JD kit but didn't help very much. It really pays to have a mech who has access too factory info do (carb) work.

Raditor guards (Devol)
Suspension (Devol)
Bike is competetive stock.

Oh yeah, Best way to gain skill & speed:
Get a coach or take lessons.
Since I have no MX skill, I have my son work with a reputable Pro rider. He gains buckets of speed after each lesson. Plus he learns to be a much safer rider.
MX is all about corner-speed, ruts, whoops and corner-speed (Did I mention corner speed?)

Good luck

Thanks very much, this is very interesting information.

I wouldn't have thought that in '07 Honda was still struggling with bogging issues. I tuned all that out of my X back in '04 on my own, but 3 years later, still, huh.
What's up with this!!??
Is the weather so different in Japan that they don't notice any of this in their blueprint/design/setup process?

Monkeywrench wrote:Is the weather so different in Japan that they don't notice any of this in their blueprint/design/setup process?

No, but their hands are a whole lot smaller so making changes to the carb is easy for them.

Look at the bright side, you probably wont have to do as much to the R model as you did to your X and you already know how to do most of the improvements and the inexpensive carb mods. Have you considered moving up to a 450R or X?

Actually the 2006 and the 2007 CRF 250R have both struggled with major carb issues related to the introduction of the 40mm carb.

Most race teams including Factory Honda are rumored to be using a modified 2005 37mm carb during actual racing.

Ron Hamp has a machined insert which knocks the diameter down to 38mm and has a tapered exit port specific to certain tracks. He says it's working well.

TDW wrote:Look at the bright side, you probably wont have to do as much to the R model as you did to your X and you already know how to do most of the improvements and the inexpensive carb mods. Have you considered moving up to a 450R or X?

You know, I thought about that... it sounds like it's going to be a new journey to get the R to rip nicely. I'm just kinda surprised to hear it seems like there is work that needs to go into a new race bike. hmmm.

I did think about the 450R. I'm leaning toward thinking that might be a bit too much bike for me. (Although there are mere teens riding them nowadays at the track!) I think if I were keeping the 250X I might move to the 450R - that way you could switch depending on ride type, mood, etc... But I still haven't ridden a 450R as of yet. I hear many great things about them, but all the guys I have talked to who praise them agree it is a lot of power to behold, although I understand it's set up to be very rider-friendly.

Funny thing is realizing I have been trying to track ride a bike that's heavier than the 450R all this time.

Is there maybe anyone who has bought an 07 250R and hasn't had to play with the carb?
Verrry interesting stuff here... seems to go a little beyond the 250X bog, as it involves stepping down the carb bore.
Hmmm again to that, I say.

I did think about the 450R. I'm leaning toward thinking that might be a bit too much bike for me. (Although there are mere teens riding them nowadays at the track!) I think if I were keeping the 250X I might move to the 450R - that way you could switch depending on ride type, mood, etc... But I still haven't ridden a 450R as of yet. I hear many great things about them, but all the guys I have talked to who praise them agree it is a lot of power to behold, although I understand it's set up to be very rider-friendly.

I know what you mean about the 450 being alot of bike/power, but Ive never ridden one either. Would be nice to have one of each but I'm thinking after riding both for awhile I would have a favorite and not want to ride the other. I know I would have to change the way I ride because rear tires dont last that long now on the 250, something with more power-look out? I'll bet the 450 would last longer and hold up better as long as it doesnt get crashed hard. [/quote]

You know guys, the more reading-up on the '07 250R I do, the more I am seeing the bog come up as almost commonplace.

Agent: I read something about Honda riders using a modified '05 carburetor... something about custom shaping it, and sleeving it, after boring it to (was it 42 or 45mm I read?)

Not meaning to turn the thread into a theory based thread... but I gotta throw this out there for thought.
(And you probably already know what the comment is...)

Why not revise and test more before releasing a bike for production? I came across countless write-ups about the Honda's handling (compared to Yamahaha), as well as power (again compared with Yamahaha)... but for such an important part of the bike (the carb) to stumble in this way... on a race bike no less... my official position boils down to: "eh?"

Kevin: if you come across this thread, feel free to chime in. I'm very curious how yours was in its stock form.

Guys thanks again, tons, for your input.
-matt

I have two sons both racing MX (Nov. & Int.) on '07 CRF250R's. They are not complaining about bogging with this bike. One of them had an '06 and we did run the PowerNow or PowerPlus inserts, whatever it was called. The '07 has had some changes even though it is still using the bigger carb. I did a quick google to find something that addresses the changes and found the following on dirtbikerider.co.uk (magazine) from the UK.
"Looking at the '07 250F there are no apparent changes. But appearances are deceiving and once you get out on the track you soon realise that Honda have been busy refining and tweaking what was already a great package.
Honda Park is deep sand which not only gives the bike a thorough workout, it also gives the rider a thorough working over. As the years tick by the bikes get better and better and I get...well, let's just say that life ain't fair!
The first thing that stood out for me with the new 250 compared to this year's machine was how it dealt with landings, especially given the track conditions. When we tested the '06 bike it bogged on landing in the deep sand so I was waiting for more of the same. But it just didn't happen - with the new carb and fuel pump on board there was no hesitance from the motor. With the jetting spot on it felt real sharp and coming out of turns the motor felt more responsive than this year's model."

Well i curently have a 07 250 and well i am only 15 and weigh round 150pounds so my bike is great for me at the moment. I never get any hesitation in the motor and love the suspension on it. I have riden a few raceing 450's and the honda is my far the best. it feels like your on a 250 with more power. you don't notice the weight. But for me being so light it had just a bit to much power. next year i am lookin to step up to a 450

Vanrock wrote: I have riden a few raceing 450's and the honda is my far the best. it feels like your on a 250 with more power. you don't notice the weight. But for me being so light it had just a bit to much power. next year i am lookin to step up to a 450

Agreed. I have just moved to the 450, and it's lighter than the 250X was. I'm 32, about 5'11 and 185 with riding gear on, and the 450 does feel light. It's very balanced. Do be careful if and when you make the switch. This is surely a machine to be revered & respected - you'll never run out of power. Be careful with it.

I think I'm going backwards. I started with an 06 45X and love it. I picked up a pumped up 96 RM125. This thing rocks. I have been riding it on small tracks and it is so much fun. The 450 rocks in the hills but for the tight stuff this thing is a blast. I went through 4 tanks of gas this weekend. I am jonesing to ride the 450. Labor day weekend I'm going to ride everything. CRF 450x, RM 125 and the new klr650. I love long weekends.
David

Bring it on! Bunch of bikes just means you love the sport, not that you can't pick just one.

El Guapo: "Heffe, would you say you have a plethora?"
Heffe: "Yes, El Guapo... it is a plethora"


See, even back in 3 Amigo times they had a bunch of stuff.

I really enjoy the light and quick. Plus I don't want to hurt my 450.