Faults:

Nothing majorly wrong has happened with this bike.

The stock clutch levers are weak and should be upgraded, but other than that, the bike performs great.

General Comments:

This bike is insanely fast from the start; the acceleration is almost like riding a 500 2 stroke and it's insanely smooth to ride. I've loved the bike ever since I first rode it.

Faults:

IN 8 YEARS I HAVE NEVER ONCE HAD A CATASTROPHIC MALFUNCTION WITH THIS BIKE. IT IS BUILT LIKE A TANK.

I replace the top end every 50 hours or so. Did I mention I race regularly in the MRANN Desert Series in the B class (Expert) with this bike? I have never had a race that I did not finish due to malfunction. I race in 100 plus heat and over 100 mile races, and never had it overheat even on the most grueling enduros.

If you maintain the bike properly, replace chains and sprockets, the occasional seal or gasket here and there, you will never have a problem with this bike. There is a reason KTM is the number one selling bike in the world and now in the U.S. They are RACE READY as KTM advertises.

General Comments:

The 2003 KTM 125 SX is a dream of a dirt bike. I have been riding since I was 6 years old - just turning 30 - and I have owned over 6 bikes, both 2 and 4 strokes from practically every make and model. I have bored this engine out to a 144cc and changed the gear ratio to fit it. I live in Northern Nevada in the high desert, and once you jet the bike correctly for your altitude and run the proper fuel ratio (40:1 for me... some run theirs at 50:1, but this is all relative to one's elevation jetting etc), you should never have any trouble - EVER - if you do, you unfortunately got the occasional lemon off a production line or it's your own fault. These bikes are very easy to maintain and really don't require much maintenance to perform well. Proper maintenance, as common sense would tell you, just makes it that much more reliable.

It is extremely fast for a 144cc, lots of low end, enough top-end at 70 mph and revs to the moon! It is light and nimble in tight sections, and smooth and forgiving in wide open and "rock-gardens" due to its ability to lug down low and rev back up at the drop of the clutch. There is a reason as well that most Pros race 2 strokes in off-road. Many of which they ride 150cc-300cc depending on the environment... They work. It will be hard for me to ever race a Japanese bike again off-road.

Faults:

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.

Faults:

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.