2003 KTM 125 SX


Above average


The one thing so far that I didn't like was the oil drain plug on the right side. Too easy to strip out by over tightening. My fault.

Guess I could say I don't like the bolts that stop the triple tree from hitting the frame. I have bent many of these. Where the bolt screws in is getting bad... but still works!! Crushed the e-box by the neck also.. but still works!!

Worries me about the chain being so close to the hydro clutch too. But once again, no problems.

General Comments:

Very happy with the bike. Very nimble, and light to handle. Quick enough, and makes a nice trail bike with the right sprocket.

One of the best web sites for support groups out there. Any questions are answered. This is a big help and makes the bike worth more... to me.

Would you buy another motorcycle from this manufacturer? Yes

Review Date: 30th September, 2006

11th Mar 2007, 18:57

What would be better for woods riding and racing, the KTM 250sxf or the KTM 125sx?

31st Mar 2007, 23:59

I own a 2003 125 SX and it is an absolute weapon off-road.. it has immense acceleration (quicker than my friends 250 SX-F) and is so much lighter and flickable through trails it makes his SX-F boring (literally).

As long as you jet it right, it will not foul plugs, and has awesome low end power and will chug along like a tractor all day. The performance for a 125 is breath taking, and the sound it makes echoing thru the woods is awesome!

Look at most of the top professional off-road riders, they prefer the two-stroke... the smile it will put on your face is worth it alone.. they are the cheaper and better choice.. 125 SX all the way!!! You won't be disappointed, GUARANTEED

9th Apr 2008, 21:51

What is the oil to fuel ratio on a 2003 125sx?


27th Jan 2009, 09:06

50:1 - 60:1, put 1 pint of best brand two strole oil in a six gallon jug and fill with premium or better fuel, works fine in both a 2003 125 SX and a 2004 250 SX...

16th Feb 2009, 22:13

I was wondering how easy these bikes are to maintain, and if so, does it cost much to maintain? Thanks.

4th Oct 2009, 14:50

I just recently purchased a 2003 KTM 125 SX, and I am 23 years old. I also own a CR 250, and the KTM is almost as good on the trail and the track as the CR 250. It's fast and has great power.

10th Mar 2010, 18:58

I just got my 2003 SX125, and it has great power, but I've fouled two plugs running 40:1 with blue marble. The bike has great power. I've moved up from a CRF150R. Can't wait to race.

2nd Apr 2013, 20:15

A KTM 125SX is best for that.

2002 KTM 125 SX


Fast when it runs, when it runs


4 pistons all during racing, finished very few races.

1 jug, miked it to find it not round.

Still uses pistons like most bikes use plugs.

General Comments:

Never in my riding life of over 40 years have I been around any motorcycle that demands more service than this KTM.

Would you buy another motorcycle from this manufacturer? No

Review Date: 26th December, 2005

9th Mar 2006, 17:26

I have to think there is a problem at the crank. Yeah, we all get a bad vehicle sometimes.

7th Sep 2006, 17:50

I hav owned a KTM 125 SX since 2002. I ve only had to rebuild it 4 times since new. I only race every second month, and the bike has been nothing but enjoyable.