2004 kx 125 enduro bike 144

[Wire hand]

Hello all.I have have been racing a kdx 200 for the last 18 years I am looking for something lighter and was considering a new bike.I want a two stroke.Riding something that isn’t green just does not seem right.I have a line on a nice 2004 kx 125.Are the 144cc builds reliable?I am 50 years old and weigh 150 lbs .I ride upper c lower b level.

[umberto]

Hi Wire Hand, welcome to the site.  I have a 2005 with a 144 Athena kit, and it has been pretty reliable so far.  The power output is pretty decent, even for my 215 (ish) pounds.

[Wire hand]

Thanks umberto.Does The a athena kit come with the light weight piston and ported cylinder?

[umberto]

I'm not sure.  My was on the bike when I bought it.

[SHLEPY]

DUDE no offense but there realy isn't much weight diff,im 50 and still ride the woods with a 500.

[Kawafornication]

You could get a KTM 150 and paint it green 🤔 they are decent bikes!

[Foxx4Beaver]

DUDE no offense but there realy isn't much weight diff,im 50 and still ride the woods with a 500.

That's my weapon of choice for the woods too!....just leave it in 3rd and roll on the power as needed.

[Wire hand]

You guys must be in great shape.Racing enduros on the kx 500 is a work out.A couple hours in the vibration alone gets hard to deal with.If you guys run the enduro cross sections at your enduros in third gear you are talented.I am going to test ride the Beta rr200 215 lbs with no fuel.The kx 125 is also light and green!

[Foxx4Beaver]

I myself don't race enduro's, but I still ride quite often...I grew up racing motocross from the late 80's thru the late 90's on 250's. I got my 500 back in the Spring of 2011, and it was the only bike I had at the time, so I used it for everything. About 3 1/2 years later I restored a 250...but, I hardly ever ride it, unless I'm just takin a rip over to my buddies to hang out and shoot the s**t...I prefer to be on the 500.
if you're having that much issue with vibration, you may want to look into having the crank balanced, a "general" port job to help smooth out the power, and throw the rubber bar mount cones in the top triple tree in the trash, and get some solid aluminum cones...all that right there, will significantly reduce vibration. I can ride mine all day and not even notice vibration. 
At 47, I'm still in decent shape...I still workout 3-4 days a week, I've always eaten healthy....but...if I had to run 5 miles...there better be a chair and an oxygen mask at the end!

[KXDINO]

I have a kx125 08 that been enlarged to 144 yz flat top piston wossner , and fully ported to suit by 2 stroke performance ,and head machine to suit, he did not like the Athena kit said the porting needed major work, it powerband is wider and more powerfull all the way thrue, if you have the last kdx200 model which I have as well you can lighten them up as well fairly easy and get more power from engine is only a pc pipe ,raise the boost ports 20 thou and machine the head to get the desired squish, front brake is weak as well which I had a custom disc made using a 270mm after market bracket that fits kx450 14 model, yes they bolt straight on and get rid of kdx master cylinder , as I had a cr250 96 master lying around and bolted straight up and now have a front brake that twice as powerfull using 2 fingers.

[umberto]

If you already have the 125, have you thought of putting a KDX 200 or 220 engine in it?  It requires a little bit of work on the swingarm and airbox, but it’s a pretty straightforward swap. I had one, and it makes a really awesome woods bike.

Another thing you might think about is adding an auto clutch to your 500. Rekluse makes one that is bolt in, or you could go with an EFM that requires a bit more fabrication work on the clutch cover (but is more durable). I have an EFM in my conversion, and it’s awesome in the tight stuff now. I think the auto clutch softens the hit a little bit, and you never have to worry about stalling.

[Wire hand]

Kxdino Power on the kdx is not the issue I have been racing this thing for a long time.It has all engine mods aside from an over bore.It started and finished 14 enduros in 2018 plus the weekend riding.But there are beginning to be parts that are not as easy to find as they used to be so I am going to give the Kdx a little easier life.When I do it will be something lighter.I have ridden a kx with the 144 kit and I liked it.I just never hear anything about reliability as far as beating the snot out of them racing off road.

[Wire hand]

Well,I do not know how I turned the picture that way but I failed at trying to fix it.
Foxx you look like you could pick the 500 up and walk off with it.Not me,I am a scronny little f****r!

[Foxx4Beaver]

Foxx you look like you could pick the 500 up and walk off with it.Not me,I am a scronny little f****r!

Lol that was a good one!!

Well the guys gave you several good options...whichever you chose I'm sure you'll be happy!...
Sweet lookin bikes you got too!

[KXDINO]

Reliability is like any machine , how you do preventive maintenance , my son raced my kx125 08 for many seasons with only a  power valve breaking but did not cause damage as they are designed not to drop in cylinder , around the 200 hr mark . we would change ring every 9 hrs  and piston and ring 18 hrs etc , do the big end and mains every year and recoat cylinder after about 4 piston changes as they wear at the bridge port , enlarging the 2 holes on exhaust side by 1mm helps this , the parts for the 125 are cheap , off course you could go longer interviews but he is a pro graded rider , the only difference on the 144 is larger piston and power valve machined as the tranny and clutch last for ever, in the reliability stakes kaws are pretty reliable , but the most reliable I had is the kx450 hands down as a bike in whole and I got all the 2 strokes and 4 stroke sizes, of course some guys wont agree but that my findings since our first mx bike kx125 a5.i have records on every bike I owned on all the parts that get replaced , it scary on how much you can spend on these machines no wonder I cant afford to drink.