250R cam in a 250X engine - need more bottom end torque and less scream

Hi All,

i recently bought a '06 250x with a 250r cam in it.

rode some mountain trails, rock and riverbed this weekend and really struggled with the bike. it is a handful.

on a flat dirt track it screams along happiest in forth with the taps wide open and that's great but in the sand and in the slower technical terrain i need it to give me more manageable low speed power without the scream. besides this, i found it tough to ride (in control) up the long steep trails because without a lot of momentum it doesnt seem to have the power to climb and i end up either choking off or crashing into the nearest bush because i am rocketing over obstacles to get up the climb.

i had a mate with me on a 230f and at some point on the way home we swopped bikes for a while - what a breeze to ride the 230f through the same riverbed and climbs - 1st or second like a tractor...very forgiving and easy to handle.

how can i adjust my bike to give me more power and an easier more forgiving ride in the bottom end without limiting its performance too much at the top end?

should i remove the 250r cam and replace it with a std 250x cam?

i also dont really want to spend huge money on the bike as i have just bought it. if making cam changes is the way to go then so be it but if i can adjust other components to give me what i want then all the better...

please advise - looking for both stock standard and "out the box" ideas please?

many thanks

i have a 250x with x cam my old bike was a 230 and the 250 even with an x cam is happy higher in the rpm. the bike is nothing like a 230 and isnt really ment to be rode the same way. 250s make high end power thats what they are made for. but an x cam or a stage 1 hot cam might bring the power down in the rpm range abit but not as low as a 230.

Sounds like a Stage 1 Hotcam is what youre looking for. The stock X cam is low-mid cam that is flat on top when compared to an R cam. The R cams boost mid-top end preformance with a sacrafice of low end. The Stage 1 will give you a boost in the low-mid range with the top end performance the same as, if not a little better than the X cam. Also, keep in mind that there are two stock X cams out there. The Ca. cam is more mild when compared to the 49 states X cam.

Hope this helps. Kevin

Edited by keviwa

the X is a slightly detuned R racebike. The 230 is a play bike. If you want to play, the 230 is the one, if you want to go real fast, the 250X or 250R are the bikes to use.

The R cam has more power everywhere. I hate to see you give up all of the awesomeness that it offers. Sprockets and gearing is where I would look.

It's possible that your problem might be a lean carb mixture.

My brother Bob and I each bought new '05 CRF250x's (only 2 serial numbers apart), and they both ran GREAT for the first year of use (both exactly the same). I've continued to ride my 250x regularly, and after 14,000+ miles it still runs great (I still haven't adjusted the valves yet).

My brother Bob's 250x sat un-used for a couple of years after the first year of use, and after sitting that long, it ran like crap in the lower RPM range.

Even after running a bunch of fresh gas thru it, it still ran like crap. That was back in 2008. His bike hasn't run since then, and it only has about 400 original miles on it.


My 250x with 14,000+ miles on it still runs great and has alot of low end punch and his 250x with 400 miles runs like a dog (at low RPM, anyway).

Brother Bob says someday soon he'll remove his carb and disassemble it to clean all the jets, and ride it again. I'm still waiting...

If your '06 250x had been sitting for too long before you got it, it may just have a clogged pilot jet, or something similar clogged.


It sounds like you want your bike to run like an XR400. It isn't an XR, and won't ever run like one. It is a 125-class bike, and needs to be ridden like a 125. You HAVE to scream it's guts out to get power out of the motor - if you let the RPMs drop on a climb, you're either going to have to flog the hell out of the clutch, or turn around and try again. The problem is really the transmission more than anything - the engine is just not suited for a WR transmission. You're lucky to use 3 of the gears (and that's if you count 1st), and you're going to need a LOT of clutch to get full power since every gear change puts you out of the engine's sweet spot. I have an '06 CRF250X and an '06 CR125 - I ride them both pretty much the same way - screaming the engine with lots of clutch work. I'd say my 250X needs even more clutch than my CR, simply because of the tranny.

So, to summarize - you're trying to make a machine into something it is not. Drop a tooth on the front sprocket (to a 13T) - that will help tighten the gears up and is one of the best improvements you can make on the bike (and it costs all of $8). Order a spare set of clutch plates, then go out and beat the balls off your 250X - that what it likes.


PS - I want a CRF2eR

Edited by jayc250x

Sounds like a Stage 1 Hotcam is what youre looking for. The stock X cam is low-mid cam that is flat on top when compared to an R cam. The R cams boost mid-top end preformance with a sacrafice of low end. The Stage 1 will give you a boost in the low-mid range with the top end performance the same as, if not a little better than the X cam. Also, keep in mind that there are two stock X cams out there. The Ca. cam is more mild when compared to the 49 states X cam.

Hope this helps. Kevin

I agree with this one. The 250x should have no problems on the trails and is the perfect bike for this type of riding. Get a Stage 1 or go back to an X cam. Doing the CCC mods or just proper jetting will also help. Didnt see what year it was, but if its an earlier model than the accelerator pump modification is a must and will cure low end bog with any cam.

Dont give up on the X. Its ten times the bike the 230 is. And althouh i am a die hard XR owner, its also a much better bike than the old air cooled thumpers.

I need the A/P mod,if I fully punch it from idle it dies.My bike did really good in lower gears and sand.Its a stock 04,X cam.Never bogged or stalled,just tractored thru.It was my first real ride in 20yrs.,didnt ride long,but I'm outa shape.

These bikes do like the higher rpm's tho.

Maybe try gearing as said above,seems the easiest and cheapest.

I did not like the R cam at all

I rode a 230 until recently passing it onto my son and buying myself an '06 250X and I experienced your same issues making the transition between bikes - we mainly ride woods with tight technical trails and hills.

My bike had the original X cam. I went through jetting procedures and got rid of the initial throttle bog but it didn't help the issues you're having. I decided to install a heavy flywheel and I gained a nice boost in bottom torque. It helped smooth out the low end throttle delivery, allows me to bog the engine lower without stalling, I no longer need to start hills screaming or wear on my clutch when RPMs drop, I have less spin out when hitting loose dirt on hills, as well as, through mud - for the most part the bike can now grunt through most everything I need it to. It still can't tractor quite as well as a 230 but it grunts better than when stock.

The heavier flywheel doesn't affect top speed but you loose a little of the snappiness. I haven't had any problems raising the front end over logs and such. There's still way more snap available than what the 230 has. It's not for everyone, but it has sure made my bike more solid for my riding situation - and makes for a more enjoyable day for me.

Trail Tech and Steahly were both highly recommended when I did my research - I went with the heaviest 250X flywheel from Steahly 12oz over stock weight (full flywheel, not flywheel weight).




Edited by Greystoke X

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