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Yamaha YZ125X Review | Bike Reviews | Features

Yamaha is doing its bit to support the resurgence of two-stroke off-road machines, most recently with the release of the YZ125X.


The YZ125X is aimed at getting our future enduro stars on board bLU as early as possible. Based on the long-serving YZ125 motocrosser, the X has a range of engine and chassis tweaks similar to those on the YZ250X to make it enduro-friendly. Plus it’s rec-reg legal in Victoria and Tassie. People often ask why it doesn’t have full rego? YMA suggested this decision comes from Japan. HQ does not want to fit the power source to accomodate the extra juice needed for ADR compliance. In other words, the ROI on a small quantity model doesn’t justify the spend required, which, frustatingly, we can understand.

I have spent a large part of my racing career on light, high-revving 125Ts and love them. I raced two International Six-Days Enduros on 125s and my last outright Australian Four-Day Enduro win was on one. The magic of holding the throttle wide open while weaving through the trees and tap dancing on the gearlever is something I’ll never forget.

I’m used to seeing a handful of European brands offering 125cc enduros, but I can’t even remember a time when Yamaha did it.

A 125 smoker can be an absolute screamer but Yamaha didn’t want to go that route. Targeted primarily at the huge American cross-country market, the YZ125X has its own rotary exhaust valve, a lower-compression cylinder head to make it more rideable and a different CDI to smooth out the delivery and widen the powerband.

Yamaha has done a great job, as the 125 is very easy to ride and usable on all kinds of terrain. On our grasstrack loop I rode it like a typical 125 – full throttle with non-stop gearchanges, but it was when I ventured into terrain more like you would find in a hard enduro that it impressed me the most.

Steep climbs where a 125 would normally suffer were swallowed with ease. Yamaha has certainly given the YZ125X more torque than I’d expected. The added bottom-end power has slowed down the revs but that’s something I enjoyed, as it only made the bike easier to ride over slippery terrain.

Riding on transports won’t be as much fun as, even with the six-speed gearbox, this Yamaha runs out of revs, partly thanks to its lowered final-drive gearing (see breakout below).

Over all the kinds of terrain I tested it on, the YZ125X felt like it had the perfect balance between rigidity and flex. It feels so settled and tracks so well over rough terrain and takes any kind of corner with ease.

A big part of that feeling is the KYB suspension. Up front the 48mm spring-cartridge fork runs softer settings than the motocrosser and that’s good news, as most MX suspension beats me up on enduro tracks. The softer setting Yamaha has chosen to go with worked great for my 83kg. It soaked up the dry, slippery terrain with ease, and never bottomed out when I got adventurous on the endurocross track. Yamaha has gone the same route with the KYB shock, which has also received softer settings for off-road conditions. Once again it has nailed things, as the rear-end felt great.

Yamaha says the seat is 20mm lower on the X and this was great for me as I love being able to get my feet on the ground when I need to and I find it makes slicing between trees easier, as I’m closer to the ground. The lower seat appears to have come from the switch to an 18-inch rear wheel which also gives riders more tyre options, plus the beefier sidewalls give improved comfort over bumps, rocks and roots.

Anyone who has ridden a YZ450F lately knows how fast a 60hp-plus motorcycle can get moving and, with that in mind, Yamaha has started fitting a very strong 270mm front disc to pull its motocrossers up. With the same front brake on the much lighter YZ125X, you have the power at your fingertips to pull up crazy fast. Getting used to how late I could leave my braking was the thing that took the most time when I first jumped on.

Every time I looked for an off-road feature, the YZ125X had it covered. There was the alloy sidestand, fuel tap with reserve position and a sealed O-ring chain. Yamaha Australia has completed the picture with lights, a YRD wiring kit, new stator with lighting coil and quality Barkbuster handguards. There’s already a good range of GYTR parts for it too, including a bashplate and bigger tank, as many bits are interchangeable with the YZ250.

I know I wasn’t breaking any lap records or speed limits during my time with the YZ125X but it was so much fun being back on a 125cc that I want to hammer one more often. Yamaha’s rideaway price of $10,949 makes it a very appealing option for off-road racers in this category compared with the rego-ready offerings.

I really believe more parents and riders should consider a 125cc two-stroke. Unfortunately all everyone seems concerned about these days is what bike they will be faster on. When you have young riders, small riders and parents all putting in their two cents worth on what bike to buy based on its speed, all roads lead to the latest generation of high-performance four-strokes. I totally understand this, but I would like to see all Junior riders limited to 125Ts, until their last year of Juniors.

My reason is that all of the new-generation 250Fs are putting out more power than most factory off-road motorcycles used to produce in the 1990s. Yes, I know that makes me sound old but at what point will riders and parents realise riding can be just as exciting and fun with less power?

It also hurts a hell of a lot less to crash a 125. I don’t think it’s by chance that I never had any massive crashes on one.

I know the cost of fixing a blown-up 125T is way less than a 250F and with every dollar counting, this can go a long way in keeping more riders on the track. Also, the skills you need to learn to ride a 125 well will always help you on a motorcycle – being in the right gear and choosing lines to keep up corner speed are priceless skills to have. I know my time on a 125 taught me most of the stuff I use to this day.

Yamaha YZ125X Specs

Type Piston-port, reed-valve
Displacement 125cc
Bore & STROKE 54 x 54.5mm
Cooling Liquid
Compression ratio 7.4 – 8.8:1
Fuel metering Mikuni TMX38 carburettor
Tank capacity 8.0L
Transmission Six-speed, constant-mesh
Clutch Wet multiplate, cable

Wheelbase 1455mm
Seat height 955mm
Ground clearance 350.5mm
Weight 95kg wet (minus lights and handguards)

FRONT KYB 48mm spring-cartridge 48mm, 300mm travel
REAR KYB gas-oil monoshock, 315mm travel

Front Nissin twin-piston, 270mm wave
Rear Nissin single-piston, 245mm wave

Running Gear
Handlebar Yamaha tapered aluminium alloy
Front tyre Dunlop AT81F 90/90-21
Rear tyre Dunlop AT81 110/90-18

Price & Contacts
Price $10,949 rideaway
Phone (02) 9757 0011
Warranty Three months parts only