KTM 125 EXC Enduro

KTM 125 EXC Enduro
Manufacturer	KTM
Production	1997 - 98
Engine	Two stroke, single cylinder
Compression ratio	12.5:1
Ignition	Kokusan digital
Transmission	6 Speed
Suspension	Front: 43 mm Marzocchi Magnum 45 upside down fork and shocks Rear: Fully adjustable Ohlins Type 3A mono shock
Brakes	Front: Single 260 mm disc,2 piston caliper Rear: Single 220 mm disc,1 piston caliper
Front Tire	90/90 - 21
Rear Tire	120/90 - 18
Wheelbase	1430 mm / 56.3 in
Seat Height	949 mm / 37.4 in
Weight	94.5 kg / 208 lbs (dry),
Fuel Capacity	9 L / 2.4 US gal / 2.0 Imp gal
Manuals	Service Manual

Engine

The engine was a Liquid cooled cooled Two stroke, single cylinder. The engine featured a 12.5:1 compression ratio.

Chassis

It came with a 90/90 - 21 front tire and a 120/90 - 18 rear tire. Stopping was achieved via Single 260 mm disc,2 piston caliper in the front and a Single 220 mm disc,1 piston caliper in the rear. The front suspension was a 43 mm Marzocchi Magnum 45 upside down fork and shocks while the rear was equipped with a Fully adjustable Ohlins Type 3A mono shock. The 125 EXC Enduro was fitted with a 9 L / 2.4 US gal / 2.0 Imp gal fuel tank. The bike weighed just 94.5 kg / 208 lbs. The wheelbase was 1430 mm / 56.3 in long.

Photos

Overview

KTM 125 EXC Enduro

Should you be riding a 125 enduro bike?

For a lot of people, that's a tough question to answer.

Sure, if you're just starting out or weigh-in at 125 pounds, it's a natural--a 125 will work great, and won't be so powerful to intimidate you. But what about the rest of us, all the 200-pounders who should know better than get on a 125? Plenty of big people and Senior class riders are looking at 125s these days, for many valid reasons.

1. They're cheap. Even though it costs the same to make a 125 or a 620 (at the factory level), manufacturers are forced by the market to price a 125 lower than a big bike.

This KTM 125 we're testing this month carries a suggested retail price of $4548, which is almost $1000 less than a 250. For that $1000, all you're getting less of is cubic displacement; every other feature on the bike is the same as the big bikes.

2. They're light. Compared to a 250 or Open bike, a 125 always weighs less. In the case of the KTM, the 125 E/XC weighs exactly 20 pounds less than the 250/300/360. Twenty pounds may not seem like much, but it's a big deal when you're tired or need every last bit of advantage to get through that tight spot or drag your bike out of a swamp. Weight is all important; if you don't believe us we'll make you race a 300-pound bike for a while.

3. They're not gutless anymore. Modern 125cc enduro bikes are an amazing combination of wide powerband and strong midrange power, while still delivering that characteristic 125cc shriek on the top end. If you think 125 machines are still horribly peaky and unridable, you need to sling a leg over a 125E/XC or a Husky 125WXE one of these days soon, and see what you think. We're almost positive you'll be shocked at the available power.

Armed with these revelations, we hopped on a 125E/XC for a day this past fall, and were suitably impressed. First of all, the 125E/XC is easy to start--actually that should be a main feature on the above list. You push the kickstarter down with a half-hearted jab and the bike lights up like it was running all along, just not making any noise. The only complaint we could possibly have is the small size of the kickstart lever.

It appears to share the same part number as the shift lever (joking--don't take that as truth), and if you have size 11 feet, sometimes you're not sure you've got enough of your big toe wrapped around the kicker to push it down without it slipping off. If you have reasonable size feet this isn't that much of a problem.

Jetting is everything on a 125, and this bike is no exception. Like a lot of KTMs, the 125 seems to come through jetted a little strange; we found it to be a little fat on the bottom and lean on top. Our jetting was dialed in by H&H KTM in Douglasville, Georgia, and for cool fall weather they had the bike jetted with a 215 main, a 40 idle jet, a K55 needle in the second position, and a DP262 needle jet. For the day we rode the bike, this was perfect jetting. The starting jet stayed stock at a #60 jet, and like we said the starting was flawless.

Once the engine is warm, the first thing you notice is the abundant low-end power. Yes, it's no 250, but you can ease the clutch out and move right along with this bike. No frantic revving and clutch-slipping required. The good bottom end eases right into a quick midrange hit that tugs the bike up to speed. When you hit mid revs you have a decision to make. You can shift up and gently ease up in speed, or you can pin it and start riding like a 125 knucklehead.

Which way you go mostly depends on terrain. If you're riding on level ground, you can do whatever you want. You can sit down and short shift all day long, and just have a nice mellow ride on a light bike. However, if the terrain points up, or if you're racing somebody for keeps, you'd be better off hanging on and letting the KTM buzz, which is can do quite well. Pin the throttle and the 125 gathers it's strength and then leaps forward, and by the time you get to about eight grand it's begging for another gear. Keep it pinned and smoothly jam it into the next gear and the bike leaps forward like a bee-stung jackass, and if you're not paying attention the back end is going to hop out of line when the rear wheel starts spinning. That's okay though, because on a 200 pound bike all it takes is a twitch from your back end, and it snaps back into line. Pin it, rev, repeat, until you run out of gears!

In the really tight, twisty stuff the low-end power definitely helps, but in hills you have to ride aggressively because yes, there's low end, but it's still a 125. If you're not used to it the first couple of ride might be frustrating, but seasoned 125 riders soon learn to shift down two gears coming into a corner or hitting the base of a hill, rather than just taking one, as you'd do on a 250. When all is said and done, riding a 125 aggressively can be a lot of hard work for your left foot, but the light weight and low inertia of the engine makes up for it.

This year's KTM is coming with the new Magnum 45 forks, which so far have proven to be a major improvement over the '95 forks, which we had mixed feelings about. The new Marzocchi Magnums seem to be valved a little more accurately for the spring weights Marzocchi likes to use. We never got a chance to tear them all apart and see what they're doing, but we did notice that the forks work better, right out of the box, than they did last year. Roots and hard-edged ruts are swallowed up with very little stress, and choppy, rough terrain doesn't know the forks out of your intended line. We like them, much better than last year, although we would recommend that everybody open them up when new, change the oil to a good cartridge oil and make sure the oil level is set accurately. We'd recommend this procedure on any bike's forks, not just KTM. You'd be surprised at how far off most fork oil levels are, even straight from the factory.

The rear suspension is provided via an Ohlins Type 3A shock, and it is confidence-inspiring to know that this is arguably the best shock absorber made in the world. The KTM engineers have done more testing since '95, and as a result the rear shocks now come with even better damper valving, which is not to say that last year's was bad.

This '96 just seemed to be a little more supple in the initial part of travel, and felt cushier without being "soft." Nice rear suspension; no hopping, no kicking up, just good control of the back wheel. However, like the forks, if you're really serious you'll let a competent Ohlins service person change the oil on this shock after break-in, and make sure that it's filled and bled with the proper oil. Nine times out of ten bad rear shock action can be traced to air in the shock or other assembly errors, and if you want to treat yourself to the best you won't take any chances.

If the 125 feels smaller than the 250, it's no illusion. The KTM 125 frames are slightly smaller; maybe an inch and a half in wheelbase. Don't expect a low seat height, however, because the 125 boasts of a seat height of 37.4 inches--two tenths of an inch taller than the 250. The seating position is typical KTM--you feel like you're sitting on top of the bike, with plenty of room between you and the handlebars, and a good relationship between the seat and footpegs. The frame is chromoly steel, while the rear subframe is aluminum.

Putting it all together and threading this bike through the trees is a blast. It feels like you're riding a mini bike, and when you find the sweet spot in the powerband you can blast all day, hopping between turns and just plain having fun. Yes, you do have to shift more, but that's part of the trade-off for all this light weight and flickability.

Incidentally, if you think you want to the 125SX instead of the E/XC, this is what you'll find: The SX weighs 10 pounds less (198.4 pounds) because of a different rear subframe and no lights. It has a PVL internal flywheel ignition with no lighting coils, and a close ratio transmission that has a taller first gear and lower sixth gear than the E/XC. It also costs about $150 less than the E/XC. Everything else is essentially the same.

Well, we only had a day on this little popper, but we wish it were longer. As a matter of fact, we wish we had one of these things in our garage. The fact that this bike is as much fun to ride as it is stands as the answer to the "Do I want a 125?" question. If you like light weight and maximum maneuverability, well yes, you probably do. This KTM 125E/XC has an excellent suspension, KTM's legendary handling, and an amazingly versatile engine. You might have to ride it a little bit harder than a 250, yeah, but along the way you're going to have a ton of fun.

Source:

Make Model	KTM 125 EXC Enduro
Year	1997 - 98
Engine Type	Two stroke, single cylinder
Displacement	124.8 cc / 7.6 cu in
Bore X Stroke	54 x 54.5 mm
Compression	12.5:1
Cooling System	Liquid cooled
Induction	Dell-Orto 37 mm flat slide carburetor
Ignition	Kokusan digital
Starting	Kick
Max Power	8.2 kW / 11 hp @ 7500 rpm
Transmission	6 Speed
Final Drive	Chain
Front Suspension	43 mm Marzocchi Magnum 45 upside down fork and shocks
Front Wheel Travel	300 mm / 11.8 in
Rear Suspension	Fully adjustable Ohlins Type 3A mono shock
Rear Wheel Travel	345 mm / 13.6 in
Front Brakes	Single 260 mm disc,2 piston caliper
Rear Brakes	Single 220 mm disc,1 piston caliper
Front Tire	90/90 - 21
Rear Tire	120/90 - 18
Wheelbase	1430 mm / 56.3 in
Ground Clearance	381 mm / 15 in
Seat Height	949 mm / 37.4 in
Dry Weight	94.5 kg / 208 lbs
Fuel Capacity	9 L / 2.4 US gal / 2.0 Imp gal
Review	Motorcycle.com

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