KX 250.... What's the best year to get?

[treedodgingfool]

First off, what bike that'll suit you best depends upon your riding conditions you intend to do most, ability, and price range. I've ridden loads of different 250 ring-dingers from all makes over the decade of working in the industry.  YZ, RM, CR, SX, EXC, EC; they all loyal followings for certain inherent traits, some abilities would notice and others won't.  My perspective comes from woods competition in the northeast US stick farms and rock gardens.  In that realm, a properly set-up "M" model KX is by far my favorite 250 mx to woods convert.  Of the two M models, '03 & '04, the '03 has the better linkage and forks for slower speed hack but the stock motor needs a simple '04 powervalve govenor spring to time the valves correctly and could benefit from a CR style front brake routing, both super cheap and super simple fixes.  The '04 on the other hand has ideal linkage set-up for whoops, a little harsher front fork but a superb motor in stock.  Why is it superb when a YZ makes more power or a RM has more response?  Because it's a 100% usable, all the time, especially as a woods convert.  Some folks are only concerned with sheer horsepower, off the track useability and durability play a much larger roll.  The '04 has more then enough to get either job done and the old school Kips powervalve holds up well to boot. 

The "R" models('05-'07), are an interesting breed. Along with my most loved, modified '03, our '04s, there sits an '07 I raced a whole season of enduros with.  I parked it to deal with it's inherent issues at a later date and ressurrected my old '03.  Why?  Maybe this particular bikes handling woes are not as present in a wide open venue like a track or desert, but the ultra steep steering head angle creates a knife and wash effect that's leveraged me on to my face more then a few times.  It took a while to put my finger on that handling quirk being the steering angle and not another factor, but it is in the case of the '06 & '07s.  Also the power.  With the same internal gear ratios as the '03-'04s, this bike delivers it's power a 1/3rd higher then the previous motors.  That means it's a softer bottom, intense mid- range (which can be fun) and 1/3rd longer pull on top.   For trail use it required a different pipe to Try and shift the power lower and some super low gearing to keep the clutch abuse to a mininum.  The spring style powervalves do make "R" engines quicker reving and more responsivebut with a harmless but annoying catch, the stupid little side center powervalve spring that likes to break.  It's easy enough to know when it happened and replace, but annoying none the less.  The "R" does noticeably feel narrower in the footpegs (about 1" diff from the M model). 

The older yet "L" were great bikes too that shared the same engine platform as the M models, but the chassis lacked some of the refinements the M models received.  The L models are still competitive in the right hands.  That's pretty much what it comes down to though, what bike jives with you best and your riding sttle.

[Motorrad]

First off, what bike that'll suit you best depends upon your riding conditions you intend to do most, ability, and price range. I've ridden loads of different 250 ring-dingers from all makes over the decade of working in the industry.  YZ, RM, CR, SX, EXC, EC; they all loyal followings for certain inherent traits, some abilities would notice and others won't.  My perspective comes from woods competition in the northeast US stick farms and rock gardens.  In that realm, a properly set-up "M" model KX is by far my favorite 250 mx to woods convert.  Of the two M models, '03 & '04, the '03 has the better linkage and forks for slower speed hack but the stock motor needs a simple '04 powervalve govenor spring to time the valves correctly and could benefit from a CR style front brake routing, both super cheap and super simple fixes.  The '04 on the other hand has ideal linkage set-up for whoops, a little harsher front fork but a superb motor in stock.  Why is it superb when a YZ makes more power or a RM has more response?  Because it's a 100% usable, all the time, especially as a woods convert.  Some folks are only concerned with sheer horsepower, off the track useability and durability play a much larger roll.  The '04 has more then enough to get either job done and the old school Kips powervalve holds up well to boot. 

The "R" models('05-'07), are an interesting breed. Along with my most loved, modified '03, our '04s, there sits an '07 I raced a whole season of enduros with.  I parked it to deal with it's inherent issues at a later date and ressurrected my old '03.  Why?  Maybe this particular bikes handling woes are not as present in a wide open venue like a track or desert, but the ultra steep steering head angle creates a knife and wash effect that's leveraged me on to my face more then a few times.  It took a while to put my finger on that handling quirk being the steering angle and not another factor, but it is in the case of the '06 & '07s.  Also the power.  With the same internal gear ratios as the '03-'04s, this bike delivers it's power a 1/3rd higher then the previous motors.  That means it's a softer bottom, intense mid- range (which can be fun) and 1/3rd longer pull on top.   For trail use it required a different pipe to Try and shift the power lower and some super low gearing to keep the clutch abuse to a mininum.  The spring style powervalves do make "R" engines quicker reving and more responsivebut with a harmless but annoying catch, the stupid little side center powervalve spring that likes to break.  It's easy enough to know when it happened and replace, but annoying none the less.  The "R" does noticeably feel narrower in the footpegs (about 1" diff from the M model). 

The older yet "L" were great bikes too that shared the same engine platform as the M models, but the chassis lacked some of the refinements the M models received.  The L models are still competitive in the right hands.  That's pretty much what it comes down to though, what bike jives with you best and your riding sttle.

Wow... Awesome first post..   way more info then I ever knew about the 250's..     

[Charlie500]

First off, what bike that'll suit you best depends upon your riding conditions you intend to do most, ability, and price range. I've ridden loads of different 250 ring-dingers from all makes over the decade of working in the industry.  YZ, RM, CR, SX, EXC, EC; they all loyal followings for certain inherent traits, some abilities would notice and others won't.  My perspective comes from woods competition in the northeast US stick farms and rock gardens.  In that realm, a properly set-up "M" model KX is by far my favorite 250 mx to woods convert.  Of the two M models, '03 & '04, the '03 has the better linkage and forks for slower speed hack but the stock motor needs a simple '04 powervalve govenor spring to time the valves correctly and could benefit from a CR style front brake routing, both super cheap and super simple fixes.  The '04 on the other hand has ideal linkage set-up for whoops, a little harsher front fork but a superb motor in stock.  Why is it superb when a YZ makes more power or a RM has more response?  Because it's a 100% usable, all the time, especially as a woods convert.  Some folks are only concerned with sheer horsepower, off the track useability and durability play a much larger roll.  The '04 has more then enough to get either job done and the old school Kips powervalve holds up well to boot. 

The "R" models('05-'07), are an interesting breed. Along with my most loved, modified '03, our '04s, there sits an '07 I raced a whole season of enduros with.  I parked it to deal with it's inherent issues at a later date and ressurrected my old '03.  Why?  Maybe this particular bikes handling woes are not as present in a wide open venue like a track or desert, but the ultra steep steering head angle creates a knife and wash effect that's leveraged me on to my face more then a few times.  It took a while to put my finger on that handling quirk being the steering angle and not another factor, but it is in the case of the '06 & '07s.  Also the power.  With the same internal gear ratios as the '03-'04s, this bike delivers it's power a 1/3rd higher then the previous motors.  That means it's a softer bottom, intense mid- range (which can be fun) and 1/3rd longer pull on top.   For trail use it required a different pipe to Try and shift the power lower and some super low gearing to keep the clutch abuse to a mininum.  The spring style powervalves do make "R" engines quicker reving and more responsivebut with a harmless but annoying catch, the stupid little side center powervalve spring that likes to break.  It's easy enough to know when it happened and replace, but annoying none the less.  The "R" does noticeably feel narrower in the footpegs (about 1" diff from the M model). 

The older yet "L" were great bikes too that shared the same engine platform as the M models, but the chassis lacked some of the refinements the M models received.  The L models are still competitive in the right hands.  That's pretty much what it comes down to though, what bike jives with you best and your riding sttle.

Wow this is just the review I was looking for. Thank you treedodger! I just bought some property in southern Oregon and was looking into something good for tight single track. Looks like I will be on the look out for an 03. Thanks

[treedodgingfool]

Thank you!  Im glad I can be of help. I found out after several enduro seasons on both the '03 & '04 that I preferred the '03s chassis 90% of the time but preferred the '04s motor,  stock to stock (both were woods modified for race duty, but the motor stock except for bolt on's).  I combined the best of both in my resurrected '03. Still, compared to a new Gas Gas EC 250, I just love this bike and have yet to find a better replacement.  Perfect combination of cornering and stability buttoned-up in a vibration/ trail feedback dampening steel chassis.  In a recent dirt rag ten best used dirtbike list, I laughed when they listed the '00-'01 CR250 but not the M model KX's.  I raced a '00 CR250, completely woods converted prior to purchasing my '03 KX at the end of the '02 race season.  All it took was one ride on the first one in and I knew it was way better then the sleepy sewing machine powered and paint-can mixer chassis CR.  Maybe they're better for FMX, but that's alright.  The YZ250 also made the list which they have good traits though I personally dont care for the chassis in the tight stuff but I was suprised by no mention of their weak center powervalve. The M models nor any other model of KX250 making that list should help keep the used prices respectful.  All the better for some racebike projects and engine shoe-horning.

[Motoroost1]

Interesting comments about trail riding the 07 250 . I trail ride my 07 250 exclusively and I have not found that extensive modifications were needed at all . In fact , I bought a brand new PC Platinum 2 pipe and silencer for it and actually got better results using the stock exhaust system . I just could not seem to get the jetting right with the PC pipe . As far as gearing is concerned , I actually had to go the other way . Instead of increasing the gear ratio from 13/51 ( stock ) , I have had better results when using either 13/49 or 14/51 . It broadens the power out a bit and makes it much easier to control ( and faster ) when accelerating hard on the trail . 13/51 would simply spin the tire hard when it came on the pipe . My only "issue" with the 07 on the trail was the harshness of the forks . I have ridden the past 2 months with a buddy that has a 2007 ( modified ) Yamaha WR450F and from what I have seen , the capabilities of the rider make the most difference .

[treedodgingfool]

Bikes are subjective to different riders in different conditions.  I like to ride a bike in the meat of the power, where the powervalves are open most of the time.  Taller gearing and even the stock gearing in the tight, technical conditions we ride and compete in means lots of clutch slipping (13/53is what I settled on).   If the '07 had bottom end grunt like a 500, then it wouldn't be such a issue with the taller gearing in my application, but even our 500 is geared lower then stock.  In our terrain and how I like a bike to respond is a lot like a trials bike or supercross bike, instant acceleration with mininum delay.  I found the stock pipe on my '07 to be too much of a mid and up pipe requiring more clutch abuse to scurry the power along into the hit.  A FMF gnarly and Q silencer did a fair job of transitioning the power delivery lower, but still has no bottom snot like the '04s engine.  More intense mid-range and more on top, but a 1/3rd less on the bottom.  The terrian we compete in requires a lot of heavy front breaking, cut and thrust riding style.  In our conditions I found the steeper steering head angle to create a knife and wash effect.  Not everybody will notice this.  I just happen to be one those folks that can tell when the sag is off, the tire profile is taller or some other annoyance is affecting the handling (its a good and bad trait at the sametime, little bike annoyances drive me nuts until I can fix them, just ask my husband). Besides, I enjoy a bike and riding the most when the bike is set-up perfectly and I do a lot of tuning to dial each bike in. I can deal with the motor but the handling quirk needs fixing in order to give me confidence in the front end reliably doing what I ask of it, everytime I dive into a corner.  

[Motoroost1]

You are obviously riding a lot more aggressively than I am on the trails  . I find that riding the 07 hard enough to keep the power valve constantly open and on the pipe all the time is just not possible on the trails that I am on . Way too tiring for me
Bottom end power is indeed a desireable thing and this is why I much prefer my KX500 over the 250 . The 500 has power EVERYWHERE and can go from lugging the motor in the verge of stalling to spinning the tire violently into a power wheelie in an instant with a simple twist of the wrist .  This does not make the 07 250 a "bad" bike , it's just much better suited to a mx race track than it is to singletrack . I still like it though and it is what it is . I probably would not buy another pipe for it again though as I found the PC Platinum 2 did almost nothing to improve the low end torque . The stock exhaust was MUCH smoother .

[Polar-Bus]

Bikes are subjective to different riders in different conditions.  

Quoted above is the critical comment. While I found your feedback to be excellent, keep in mind, different riders like different setups. I buddy of mine is a 30 year  NETRA A vet, and he dislikes KTM's and KX's. He's told me "if i'm going to spend MY money, not a sponsorship ride,  he actually (at this time) prefers modded YZ 250cc 2s.  So bottome line is race what YOU specifically feel "comfortable" on.  Again, great feedback on KX's .  They will always have a warm place in my heart as well over the past 25 years i've ridden them !