Yamaha YZ125X Evaluation: Specs You MUST Know Earlier than Shopping for

Serious about shopping for a Yamaha YZ125X however don’t know if it’s “the suitable bike” for you? Perhaps you’re searching for your first off-road bike, or maybe you simply need a light-weight enduro bike that’s enjoyable and straightforward to experience – regardless of the case, you’ve discovered the suitable article!

On this evaluate, you’re going to study what sort of filth bike the YZ 125X is, what makes it completely different from different bikes, why it could or is probably not best for you, and what to anticipate when shopping for and driving one so that you just save money and time!

What’s the Yamaha YZ125X?

It’s a 125cc 2-stroke enduro bike for off-road driving and racing – it’s based mostly on the YZ125 motocross bike, however there are some minor variations that make it fairly a bit completely different when driving.

A stock 2021 Yamaha YZ125X 2-stroke enduro bike sitting on a stand

Who’s it for?

It’s a surprisingly versatile bike, which means you’ll be able to have enjoyable driving it on many sorts of trails or tracks. It’s an amazing bike for teenagers, adults, and even ladies if you would like one thing, enjoyable, light-weight, and barely tougher to experience – with out worrying about having “arm-ripping” energy like a 250 or 450 enduro bike has.

Perhaps you’ve already had 250s, 300s, or 450 for fairly a number of years, however having a 125 could be nostalgic for you. There are numerous older guys of their 50s and even 60+ that return right down to a 125 and say that “That is probably the most enjoyable I’ve had on a mud bike”.

Engine – what to anticipate

Because it’s based mostly on the motocross bike, the YZ125X has the identical 125cc 2-stroke liquid-cooled engine, however with some minor tweaks to make it simpler to regulate. The principle distinction is that the facility valve has a special form and opens later – this provides you a softer hit, however barely improves low to mid-RPM torque, which is nice for path driving off-road.

The cylinder head has extra quantity, which lowers the compression. It loses some energy potential, but it surely additionally signifies that you don’t want fairly as excessive of octane in your fuel.


The highest-end horsepower is about 34, which is fairly near the identical because the MX mannequin. That’s not what makes the YZ 125X an amazing bike, although, as a result of it’s fairly a bit decrease on peak energy than the European 144cc enduro bikes (i.e. KTM 150).

The 125X is nice as a result of it has a smoother energy curve that’s simpler to deal with for those who’re transitioning from a midsize Yamaha filth bike, such because the YZ85 or TTR125. With extra predictable energy, it’s simpler to remain in management with extra traction and is much less tiring than the snappy motocross engine.

Prime velocity

Max velocity is about 60 MPH, which doesn’t actually matter until you might be racing out within the desert on high-speed terrain. If you wish to improve your YZ125X prime velocity, simply put a smaller rear sprocket on it (Amazon).

You’ll lose slightly little bit of acceleration and 1st gear will likely be noticeably taller, however for those who’re not doing tight and technical path driving then it shouldn’t be a difficulty.


The YZ 125X shares the identical 6-speed transmission because the 125 motocross engine. The one gearing distinction is that the 125X makes use of a 50-tooth rear sprocket vs a 48 on the YZ125 MX bike.

This offers you barely decrease gearing for higher slow-speed driving on slim trails in addition to faster acceleration. You lose slightly little bit of prime velocity in sixth gear, however that’s not a giant deal until you’re cruising at excessive speeds, which isn’t what this Yamaha filth bike is made for.

2020 Yamaha YZ125X Yamaha YZ125X Review: Specs You MUST Know Before Buying

Carburetor – coping with jetting

Whereas the European bikes are going fuel-injected, even on the small-bore 125’s and 150’s, the YZ125X nonetheless has a carb. That is completely positive for those who favor fewer electronics and a less expensive price ticket.

Jetting is comparatively simple, particularly with the brand new PWK38 carb. If you happen to’re anxious about tuning the jetting, I will help you get began in only a jiffy (click on to study extra).

Path mods

Yamaha particularly made the YZ125X to be extra comfy and sensible driving off-road, which they did with an 18” rear wheel, softer suspension, and a kickstand… However there are a number of elements that consumers and Yamaha lovers are nonetheless asking for.

Why didn’t they embrace them? To maintain the value down, primarily. For them, and for you – the customer. This fashion, it’s cheaper to purchase the filth bike, after which you’ll be able to customise it with your personal aftermarket elements if you would like.

2021 Yamaha YZ125X 2 Yamaha YZ125X Review: Specs You MUST Know Before Buying

Elements Yamaha forgot so as to add

First, a much bigger fuel tank could be good because it’s the identical capability because the motocross bike. For off-road driving, you could be on a protracted experience, so with the ability to experience additional with out filling up could be a pleasant improve. A minimum of it has a “Reserve” on the petcock in order that you understand when it’s getting low in case you are driving within the “ON” place.

Does it have a spark arrestor?

Subsequent, Yamaha forgot so as to add a spark arrestor to the silencer! Certain, it’s a contest mannequin for racing. However the place I dwell, you want a spark arrestor to race a hare scramble or enduro, in addition to experience on state trails.

Electrical begin?

There’s a kickstarter, however no electrical begin, which the European 125 enduro bikes have. Nonetheless, this makes the 125X less complicated, particularly because it doesn’t have a battery to fret about going useless.


The 125X doesn’t include a headlight or tail gentle, which isn’t as large of a deal. If you wish to add one, then you definately’ll most likely must improve the stator as a result of it doesn’t produce sufficient juice to energy up a lot for lights.


One of many many good options of the Yamaha YZ125X is the suspension – it has the identical elements because the motocross bike model, however some inside adjustments make it extra comfy for off-road driving.

The largest distinction between the YZ 125 and 125X are that the 125X mannequin has softer valving, however what does that imply? Properly, it’s nonetheless good for those who’re within the 150-180 lb weight vary, however the forks and shock will compress and rebound faster on slower terrain.

That is nice for off-road driving as a result of it should absorb the bumps and small obstacles higher for a extra comfy experience. Compared, you probably have the MX suspension, you’ll “bounce” off of the small bumps extra and get fatigued extra rapidly.

Entrance forks

Similar to the Motocross mannequin, you get the identical totally adjustable entrance forks. This implies you’ll be able to alter the compression and rebound clickers externally with a easy screwdriver.

By tuning these clickers, you can also make the forks really feel stiffer or softer as a result of these “damping clickers” management how briskly the forks transfer out and in. If you have already got the right fork spring charges, then these clickers are the “fine-tuning” adjustment to get probably the most consolation and traction – most individuals don’t even contact them in concern that they’ll mess one thing up, however you’re doubtless lacking out on a better-performing filth bike!

Rear shock

The rear shock on the YZ125X can be totally adjustable, together with spring preload and damping. After getting the right spring price in your weight, you should alter the shock preload to get the right experience peak in order that it handles properly.

Then, you’ll be able to alter the low and high-speed damping clickers, which work equally to the entrance forks. By getting each the entrance and rear suspension working collectively, you may get your YZ 125X dealing with properly earlier than you strive sending it out to knowledgeable tuner!

Dealing with 

One of many greatest benefits to driving a YZ125X over a much bigger enduro bike is that the dealing with is nearly nearly as good because it will get for full-size off-road bikes. Not solely is it light-weight, making it simple to show and deal with for those who’re not very sturdy, however the Yamaha YZ chassis is confirmed to deal with very properly!

In comparison with a much bigger 2 stroke or 4 stroke, the 125 feels virtually like a mountain bike with an engine and strong suspension. 


The moist weight of the YZ125X is 212 kilos, which is barely 3 lbs greater than the MX model. In comparison with the KTM 250 XC 2-stroke enduro bike that weighs about 234 lbs, the 125X is over 20 lbs lighter, however that’s solely half the story.

The precise weight of a mud bike is essential relating to dealing with, however the dimension of the engine issues too. For instance, the 125cc engine will really feel noticeably lighter than a 250cc as a result of the rotating mass is much less. This additionally makes it much less exhausting to experience – an essential issue to contemplate if you wish to do lengthy path rides or endurance races.

Seat peak – what dimension rider is the YZ125X for?

With a 38.2-inch seat peak, the YZ125X is about as tall because it will get for an off-road Yamaha bike. Whereas your inseam performs a job, this filth bike is an effective dimension for those who’re 5’8”-6’2” tall, however that doesn’t imply it received’t work properly for those who’re shorter or tall than that.

For instance, for those who’re quick (like me), then the very best factor you are able to do, except for selecting a shorter bike, is to enhance your stability approach. With extra confidence, you received’t must put a foot down till you should come to a cease.

Are you able to decrease the seat peak on a YZ125X?

If wanted, there are some methods to decrease the seat peak of your 125X. One of many best methods is to put in a decreasing hyperlink (Amazon) that lowers the rear by about 1.5”.

It should have an effect on the dealing with, particularly for those who don’t decrease the entrance forks to stability the suspension, but it surely’s a straightforward mod to swap again to inventory when you don’t want a lowered filth bike.

YZ125X Specs & dimensions

Listed below are the bodily specs from Yamaha’s web site:

Spec YZ125X
Producer Yamaha
Engine 125cc liquid-cooled 2 stroke
Transmission 6-speed close-ratio handbook clutch
Seat Peak 38.2” (97cm)
Suspension Journey 11.8” / 12.4”
Weight (Curb/Moist) 212 lbs
Horsepower 34 HP
Prime Pace 60 MPH
Value (New MSRP) $7,099

Mannequin 12 months historical past & adjustments

Yamaha simply began making the YZ125X for 2020. Nonetheless, the 2023 mannequin acquired some pretty vital updates that the MX mannequin obtained in 2022.

So, for 2023, the YZ125X has new inside engine updates, a carburetor, consumption, and a flatter seat, all including as much as a noticeably extra highly effective engine and modern-feeling ergonomics. These adjustments make it extra satisfying to experience and extra aggressive with different manufacturers of enduro bikes.

Reliability – how lengthy will it final?

Yamaha is dedicated to creating high-performance filth bikes which can be additionally dependable, and the YZ125X isn’t any completely different. If you happen to’ve ever owned a YZ125 MX bike, then you understand how sturdy they’re.

Chances are you’ll solely get 20 hours on the highest finish for those who’re an knowledgeable rider that holds the throttle huge open more often than not, however the YZ125X is dependable sufficient to final properly over 100 hours earlier than needing a rebuild. You simply must do easy upkeep to forestall a significant engine failure.

Any widespread points?

Although the YZ125X has solely been out for a number of years, we all know that it doesn’t have any widespread issues as a result of it’s virtually equivalent to the YZ125 motocross mannequin – and that bike doesn’t have any obvious points.

Simply keep in mind to maintain the air filter clear, change the oil commonly, and use high quality contemporary fuel and 2-stroke oil, and also you shouldn’t run into many issues with this filth bike.

Is the YZ125X the suitable filth bike for you?

Nonetheless can’t resolve if it is a good filth bike so that you can purchase? Listed below are some sensible benefits and downsides of proudly owning and driving a YZ125X:


  • Light-weight for full-size enduro bikes
  • Path equipment make it extra fascinating for off-road vs the YZ125 MX bike
  • It’s extra reasonably priced than the European bikes
  • No EFI or electrical begin to fear about
  • It’s simple to kickstart
  • Extra reasonably priced to purchase and preserve in comparison with the competitors
  • Smoother and controllable energy in comparison with an MX bike or larger enduro bike
  • Nice suspension and dealing with


  • Tall and nonetheless has fairly a little bit of energy – not good for those who’re a newbie
  • No electrical begin
  • No EFI
  • Not many on the market used
  • Underpowered in comparison with a KTM 150

How a lot does the Yamaha YZ125X price?

MSRP on a model new YZ 125X is $7,099, which is over $1,100 cheaper than the KTM 125 XC, which supplies you the spare money to spend on driving or doing your personal mods & upgrades.

For the reason that 125X has solely been round for a number of years, discovering a used mannequin to purchase could also be slightly troublesome. Nonetheless, they are often discovered within the 5500-7000 greenback vary, relying in your location, the mannequin 12 months, and the situation of the bike.

YZ125 vs YZ125X

Folks stored asking Yamaha for a 125 two-stroke enduro mannequin, which is why they took the YZ125 MX bike and made some slight however crucial adjustments to make a reasonably reasonably priced alternative.

The largest variations on the YZ125X are the softer suspension, smoother engine with extra torque, a kickstand, an 18” rear wheel, and a 50T rear sprocket for higher acceleration and a decrease 1st gear for tight path driving.

The YZ125 is a good choice if you want to start racing motocross
2006 YZ125; Yamaha set the usual for 125 2-strokes in ’06.

Learn to path experience with confidence

The Yamaha YZ125X is a good filth bike for path driving, however for those who’re nonetheless struggling to remain in management then it’s most likely since you’re simply making an attempt to determine it out by yourself. Whereas it’s attainable to do (talking from expertise), it takes lots longer to construct your confidence if all you’re doing to advance your expertise is “simply driving extra”.

If you wish to enhance your ability and confidence a lot faster so to experience sooner whereas decreasing the chance of damage, then I need to assist you to out. I’ve a primary strategies information that I need to offer you as a present for studying this far – click on or faucet right here to obtain it at this time.