Can you make a KX250 lug like a KTM 300?

[divebobber]

I want to get a 2 stroke to add to my collection for when my older son comes home on leave. Right now I have a yz250f and 426F I keep reading how yz250 2 strokes are great woods bikes because you can tune them for down low power, but what about the Kx250? My son had one a few years ago but it seemed to be all hit and not a lot of low end. Can it be tuned with power valve spring changes and woods pipe? How is it for luggability when done right?

Thanks

[Atrus96]

You know my 95 KX250 lugs great and it has a works pipe and a factory sound silencer. It does really well, so well that with a gnarly pipe and a gearing change maybe the rear rim from 19 to 18 inch and these things must just grunt there way down the trail. I have heard that 98 is the best motor but I think the 94 - 96 are the best grunters. Don't know if any of that helps but hey I tried lol.

[KX02]

It would really depend a lot on the year of the bike in question. My 05 does not have much down low, even after attempts to boost the power. Some older KX's had plenty of low end torque.

[divebobber]

I'll have to try some older Kx's. I HAVE been looking at KTM just because they have such a rep for low end torque. I've ridden a 2001 300 that was very good down low but would like to find something cheaper.

[Slick_Nick]

This is the reason lots of people go with the KX/KDX hybrid setup.

[Elementx665]

my 02 has lowend like it anit nothing. i think the 00 to 02 have the best lowend...i threw a 13t front and 51t back on mine tho ^.^

[The Spanky]

my 02 has lowend like it anit nothing. i think the 00 to 02 have the best lowend...i threw a 13t front and 51t back on mine tho ^.^

Compared to what? I think the low-end on my '02 is a bit soft, especially when compared to the strong low-end torque of the '97-'98 KX250. My '91 KDX250 had way more low-end.

The KX250 isn't bad on the bottom...for an MX bike. It doesn't compare to the KTM300, because the 300 is a much larger engine, and because the 300 is tuned for strong low-end torque, like most off-road bikes.

[Fat Tony]

I have an 01 and I am pretty happy with it in the woods. I can let the rpms drop nearly to an idle in super tight single track and just twist the throttle without the use of the clutch and it picks right back up. It seems to have very predictable and controlable power on the bottom to me.

[divebobber]

My '91 KDX250 had way more low-end.

Ok, so is the KDX 250 as reliable as the venerable KDX200? I've heard over and over how great the 200 is for tight trails but almost nothing about the KDX250.

[The Spanky]

I had mine for 14 years, and did nothing besides regular maintenance and rebuilds. The engine was essentially an '89 KX250 engine, with slightly different porting, different ignition curve, smaller carb, heavier flywheel, and wide-ratio tranny. It was dead-reliable.

You don't hear much about the KDX250 because there were never very many of them. They were only made for four years, where the KDX200 was made for at least fifteen years.

[Gotlabs]

I've got an 02, stock gearing, PC platinum and vforce reeds/cage that was way too peppy in the woods for me. I added an 11oz FWW today and it feels like a different bike. Way more luggable, and it only takes a quick twist to get the power back on if I need it.

[woodsrider73]

a kx250 makes a great trail weapon with the right mods. i have an 03 which is supposed to be lacking on low end compared to other year kx's. i have set it up for the woods with 11oz fww, v-force 3, fmf gnarley and shorty silencer, fmf supplied p/v governer spacer, and up 1 tooth in the rear. the fww and the gnarley pipe were the most noticeable mods. they made it a completely different machine, it requires much less clutch action and it lugs 100% better than stock in the tight rocky single track of the NE. noticeable difference on the hillclimbs as well. i am very happy with it but i don't think it'll ever be quite as luggable as a ktm 300.

here is some good info on converting the kx.

http://www.john-stichnoth.com/GreenMachine.html

[Wandell]

Sounds like a flywheel weight makes a huge difference.

[llamaface]

I want to get a 2 stroke to add to my collection for when my older son comes home on leave. Right now I have a yz250f and 426F I keep reading how yz250 2 strokes are great woods bikes because you can tune them for down low power, but what about the Kx250? My son had one a few years ago but it seemed to be all hit and not a lot of low end. Can it be tuned with power valve spring changes and woods pipe? How is it for luggability when done right?

Any modern 250 2t can have 'decent' low-end power, but it will be nowhere a near an offroad 300 in that respect. However 300-ish cc kits are readily available for kx250's if you want a proper big bore.

I have a 2007 kx250 (12 oz fww, gnarly pipe) and a 2009 wr300. The difference in low-end (like right off-idle) torque between the two is dramatic and unmistakeable.

[Jeekinz]

Compared to what? I think the low-end on my '02 is a bit soft, especially when compared to the strong low-end torque of the '97-'98 KX250. My '91 KDX250 had way more low-end.

The KX250 isn't bad on the bottom...for an MX bike. It doesn't compare to the KTM300, because the 300 is a much larger engine, and because the 300 is tuned for strong low-end torque, like most off-road bikes.

I can't compare many bikes because I really only ride KX250's. But I can tell you that with whatever bike, the proper gearing and pipe will be fine for most woods riding. My 05 can even lug along up a hill, off the pipe, with no problem. I rode my friends 07 YZ250 and I can tell you that I like the power output of my KX's alot better. The ergos of the YZ are pretty good, along the lines of my 05 KX250, but I couldn't really tell a big difference between the 07 YZ and my (properly geared and jetted) 05 KX.

I will tell you that the 05 chassis just ROCKS! It turns alot better than my 2000, my 94 turns pretty good but not like the 05. The 05 is alot thinner too. Took me a bit to get used to it, actually I'm still getting used to it.

If you're looking for an older bike I would suggest a 94-98 KX250. 99-01 (don't know about the 02's) have a real tall 1st gear. Again, not sure about the 03-04's either. But my 05 has a decent tranny.

[divebobber]

Well, you might call me impulsive, but I just bought a 2002 KDX220 for 1200 bucks. Couldn't resist. Obviously nowhere near the hit of the KX250 but it looks like there is a lot of modifying that can be done to make it pretty quick. As it is, it has excellent torque down low. Can't wait for it to stop raining. Thanks for the replies.