03 vs. 04 KX250

[69HemiGTX]

Is there really that much of a difference between the 03 and 04?  I know the front brake line was directly routed in 04 (because Honda's dick move patent finally expired), but other than that, what else?  Anything significant?  I tried to download the specs for them, but either the links are dead or they don't work on a government computer.

[umberto]

They made some changes to the motor and changed the rear linkage to go through the swing arm. I have an 04, and have had a couple of 03s (Goliath and a bike I flipped on Craigslist), and the differences are pretty subtle. I like the 04 motor, but the 03 may handle a little better. You can't go wrong with either year in my opinion.

[69HemiGTX]

Ah yes, the linkage.  I forgot about that.  The 04s are very easy to spot because of the linkage pivot bolt caps in the swingarm, the old engine, directly routed front brake line, and the ribs on the chassis above the footpegs.  I missed an 04 about 20 miles away by half an hour not long ago.  I'm still kicking myself over that one.  I've read your description of the 04 vs. the later models, and while the differences could be noticed by an experienced rider, I'm essentially a beginner to motocross, so I doubt I would notice anything.  I'm like Ricky Bobby.  "I wanna go fast."   

[KXDINO]

Great bikes , had both bought new, 03 needs more top end power which is easy to cure with pc pipe and power valve shim , if you want more team green spec port job and do the head for squish , i think it was mxa many years ago that modded one to produce 52 hp at the wheel , which would beat any 17 models 250 2t .if i was going to go that far i would balance the bottom end to.

[zz3gmc]

Ive also had both bikes. My wife and I race enduros and we both bought 03s new. When the 04s came out she was able to get Team Green support and picked up a new 04. I was still on the 03 and didnt think there would be much difference between the 2 until I rode my wifes 04. We are both A level enduro riders and I could tell the 04 was superior to the 03 right away! The engine has more low end power and a smoother transition into the midrange with maybe a little less over rev. I never was completely comfortable on the 03 in deep whooped out sections. Even after a revalve and respring for my weight. It wasnt bad but always felt busy. The 04 by comparison would flat out eat whoops up! The 03 suspension was better in the rocks and roots. I ended up swapping a set of 03 forks onto my 04. My wife did the same as well as swap a shock from our 07 onto her 04. the 07 has Hi speed compression adjustment and really improved the handling. She still has her 03 and her 04 which is now a 295 big bore. My 04 became a 500 conversion. She later bought a 07 and that turned out to be a major disappointment! No low end, monster mid hit, quirky handling. We still have it and Ive been tinkering with it and have got it to the point where its pretty decent. Still doesnt hold a candle to the 04!

[KXDINO]

did you ever do the frame angle mod or less off set triple clamps to fix the handling on the 07 ? i did heaps of development on my 06 , i treated it like my own personal works bike , it now a keeper. dont ride it much any more as i have 11 bikes , as i getting older i tend to ride the easier to ride kxf 250 and 450 bikes , and the kdx 200 for forest work were u need rego.

[umberto]

did you ever do the frame angle mod or less off set triple clamps to fix the handling on the 07 ? i did heaps of development on my 06 , i treated it like my own personal works bike , it now a keeper. dont ride it much any more as i have 11 bikes , as i getting older i tend to ride the easier to ride kxf 250 and 450 bikes , and the kdx 200 for forest work were u need rego.

What offset triple clamps help the 06s?  I know you said relaxing the head angle to 26.5 helps, but could you fix it with triples and not have to weld the frame?

[zz3gmc]

I havent done it yet. Every time I think Im ready to do it something else pops up and takes cash away from the project. Hopefully sometime this year. I also have a couple other bikes to ride so it sits alot.

[KXDINO]

i never tried a different offset on 05 on wards but i read somewhere they did and they used rg 3 which not 100 percent sure were 21.5 mm, i think std 25mm . i also see pro-circuit are doing a run of new clamps for these bikes but they dont give out what off set they are ,if you ring them they should tell you , i personally would just do the frame mod as 26 degree head angle is to steep , as most bikes are in the range of 26.5 to 27.5 and handle good , kawi went from 27 on the 04 to 26 on 05 onwards and didnt change the off set at all as well it sits up in the rear as well , i like the 26.5 frame mod with the 3mm longer link gold valve front and back and change the small base valve spring from std 2.58 to a 2.2 spring this is a good improvement for plushness just in it self while u got the base valve apart replace the plastic free pistons with rt alloy ones as i replaced many a set of kyb plastic ones on yz and kx that have smashed them self to pieces , these forks work a lot better after this, about the engine i tell u personally another day there a bit in that.