Country cross motorcycle Yamaha YZ125X 2021. Test and differences from the YZ125

The 2021 Yamaha YZ125 has just a couple of differences compared to the 2021 version, but they are pretty obvious. Firstly, the front number plate and side panels are blue plastic rather than white. In addition, the graphics on the plastic of the radiator have been changed, and the fork guard is made of black plastic instead of white. In general, despite the incessant jokes that Yamaha has been selling the same YZ125 model for 15 years, this is not entirely fair.

Yamaha YZ125 changes

Here is a list of changes to the Yamaha YZ125 since 2006:

2007: The fork stays have become thinner, and a thick Protaper Contour has been installed instead of a steel steering wheel. Where possible, steel bolts were replaced with aluminum ones. The perforated section of the muffler has been shortened by 75mm to improve response

2008: The YZ125 gets the front caliper, fork stays, chainguard and lower fork mount from the then YZ250F, as well as a new reed valve. The front master cylinder piston is 1.48mm smaller

2009: steel brake hose holder replaced with aluminum

2010: when there's no other update news, the makers say they've updated the graphics and made the decals on higher quality vinyl. This is exactly what happened to the YZ125 in 2010

2011: Yamaha made the perforated section of the muffler 75mm longer, but increased its diameter by 3mm to improve cross-country ability. The previous 410 main jet was replaced with a 430, and the 6BFY42-3 needle was replaced with a 6BFY43-3

2012/2013/2014: Games with colors and graphics, in particular, changing the color of the rear wing from blue to white and back

2015: Yamaha has updated the design of all the plastic, bringing it closer to the appearance of the four-stroke YZ-F, and in addition, the airbox has been updated

2016: gold chain, black rims, new graphics and higher quality vinyl

2017: the front brake disc has been increased from 250 to 270mm, and the brake pad material has been improved

2018/2019/2020: blue rims instead of black, and, of course, new bright graphics and higher quality vinyl

2021: blue front number plate and side panels, black fork guards and new graphics

Yamaha YZ125. Well forgotten old

Of course, in an ideal world, the ideal manufacturer would monitor consumer requests and respond to them with new, shiny, chicly equipped and technologically advanced products every time someone on the Internet once again complained that a particular model has not changed in a long time. In the case of the Yamaha YZ125, the only thing that really needs improvement in the current version is the engine power.

Think about it: the Yamaha YZ125's aluminum frame is one of the best in its segment. It's as close to the feel of chrome-moly steel frames as you can get. Is it worth abandoning the proven design in favor of another rigid diagonal frame? Not really. Is it worth getting rid of the 2006 model fork and installing something newer? And there is nothing “newer” that works as well as the 2006 Kayaba SSS. Then maybe a narrower tank, solid side panels and more paint options? Why not, but there is still debate about the new 2021 Honda CRF450 - does it look better than the previous one, worse, or has it even become GasGas.

And new technologies always mean a new price. In the end, it turns out that the Yamaha YZ125 is the proverbial “if it’s not broke, don’t fix it”: the model is quite good in its current form, and one of the factors of its attractiveness is the simplicity of the device and the pleasant stability of the design and construction. Therefore, this model is valued quite highly in the secondary market, there are plenty of spare parts for it, and it copes with its tasks.

YAMAHA YZ125X OFF-ROAD 2-STROKE: Full Test

The 2020 Yamaha YZ125X seems like a risky move. This is a full-size 125cc off-road two-stroke engine. You have to go back to the 70s to find anything remotely similar from Japan. There was once a market for 200cc dirt bikes in the US, but that was a long time ago. However, it could be the answer in an industry that needs new entrants to replace aging ones. Yamaha seems to be rolling the dice as an investment in the future, but in reality there is no risk

big.

NEW THINKING, OLD TOOL

The 2020 YZ125X two-stroke is the off-road version of the YZ125 motocross bike. The YZ125X looks almost exactly like the 2020 YZ125, which in turn looks like the 2015 YZ125. This was when the bike received its final makeover, and even that was mostly superficial. The core tools and design have been around since 2005. All other Japanese manufacturers abandoned the 125 two-stroke during this period, but Yamaha saw nothing wrong with keeping the bike in line for the two-stroke faithful. This bike has been a solid seller ever since. For 2021, Yamaha actually expanded its two-stroke offerings with the YZ250X, which was the first off-road two-stroke since the 1998 WR250. Now 125 are receiving similar treatment. The exterior changes that turn the YZ125 into an X are the 18-inch rear wheel and stand. There are some significant other changes to the engine. The combustion chamber is larger (10.1 versus 8.4 cc). The power valve has been redesigned and its regulator has a stiffer spring, which allows the valve to open later and more slowly. Ignition timing has also changed, with a 5-degree increase at low and mid-rpm. The X still uses the same KYB suspension components, but the valving is lighter for off-road use.

The Yamaha YZ125X SUV looks almost identical to the motocross version.
The kickstand and 18-inch rear wheel are big giveaways. Unlike the 250X, the gear ratios are the same as on an MX bike. It remains a fairly close six-speed ratio, but final gearing is lower due to the 50-tooth rear sprocket. Another thing that is similar to the MX motorcycle is the fuel tank capacity of 2.1 gallons. Yamaha could have gone a little crazy with a bigger tank, battle rails, and maybe even a headlight, but that would probably have been a setback for the whole project. The price had to be low. The 125X retails for $6,699, which is $100 more than the MX bike. Recently, European manufacturers have returned to the 125 two-stroke category with their off-road bikes. There's the $7,999 Beta 125RR, the $8,399 TM EN8,695, the $8,399 Sherco SE150 Racing, the $8,899 Husqvarna TE8799, and the $8,399 KTM EXC. The last three have electric start. The Yamaha's price is a big part of the appeal.

Yamaha engineers made changes to the combustion chamber and power valve to make the X more capable off-road.

Scheme and cry

Riding any 125 on the trail is an adrenaline exploration.
You have to be excited and aggressive to keep it on the bubble. With X you can release the clutch for flat sections of the trail. It has a lower valuation than Yamaha stock and the hit isn't as strong. If the track turns and goes uphill, you need to be prepared for a downshift or some unusual clutch action. After that, you should be prepared to upshift quickly because the engine doesn't rev nearly as high as a modern four-stroke. The 125X is not for sleepy trail rides. This is for driving fast and playing racing. It suits almost everyone who rides it because the bike works like magic. It makes you want
to ride hard. In our scale, the bike weighs 204 pounds without fuel. It's only a few pounds heavier than the motocross version. Riding a bike that lights up makes you a superhero.

We got to ride the bike in the woods of South Carolina to test its true off-road capabilities, and then we rode it in Southern California.
It was fun everywhere. You can get away with almost anything. We spent a lot of time riding the 2020 KTM 150XC-W, which is a couple pounds heavier, but riding this bike is a completely different experience. In short, this is a more powerful and capable motorcycle. It has more torque, more average, and revs higher. Overall, the Yamaha has the upper hand because it feels much smaller and lighter. Additionally, the Yamaha's suspension is outstanding. It's well balanced and the overall action is super chic. This is

bland though. The bike is tuned for young riders. This would be a great bike for kids moving up from the mini motocross ranks. It's also a great car for older riders who don't want to carry around 450 on the track. Most 40+ off-road riders don't know this, but they'd be a lot happier on a 125. This particular 125 has the advantage of running very cleanly at low speeds. It still doesn't make much power, but you can't kill the motor by grabbing too much gas on the flat. It takes the stress out of your trip.

CROSSOVER FACTOR

The YZ125X has so many similarities to the motocross version that most riders would have a hard time telling the difference without a side-by-side comparison. You can take the X straight to the motocross track and race without sacrificing it. We know because we did it. Pete Murray raced his bike around the Glen Helen REM track. This particular track is so tight and technical that soft suspension doesn't make much of a difference, even for a 170-pound rider. At the Glen Helen National Track it's a different story.

Our test bike came with handcuffs, but the stocker did not.
We'll forgive that given the $6,699 price tag. The motorcycle is too soft, both in terms of suspension and power. In any racing situation, the 125X will likely find itself outclassed by the European 144cc two-strokes, and it even gives up a slight advantage to the YZ125 MX bike. Even though its handling is phenomenal, it would take a lot of work to make up for the 10 horsepower or so by simply diving into corners harder and braking later. The real thing about the YZ125X is that it's a fun ride. This is where it beats almost everything on wheels.

Dunlop AT81 tires are in stock. The rear is 18 inches.

We don't know if Yamaha's investment will pay off in the future. We know the off-road world as a whole just got a little better with the inclusion of the YZ125X. This is a bike that is so good that it makes dirt biking in general more appealing.

2020 YAMAHA YZ125X Engine Type: Kick-start, two-stroke, valve body Displacement: 124cc Bore and Stroke: 54.0mm x 54.5mm Fuel Delivery: 36mm Mikuni Carburetor Fuel Capacity: 2.1 gal. Transmission: 6-speed Light Coil: No Spark Arrestor: No EPA Legal: No Weight, without fuel: 204 lbs. Wheelbase: 57.3" Ground Clearance: 13.8" Seat Height: 37.6" Front Wheel: Dunlop AT81F 90/90-21 Rear Wheel: Dunlop AT81 110/90-18 Fork: KYB, adj. rebound, comp, 11.8” Shock KYB travel, piggyback, adj. preload, comp, rebound, 12.4” Country of Origin: Japan Price: $6699 Importer: yamahamotorsports.com

THUMBS UP

• Excellent overall handling
• Light weight
• Inexpensive
• Reliable
• Funny!

LETTERS DOWN

• Gives power up to 150
• No electric start
• No pens
• No spark arrestor

Yamaha YZ125 on the dyno

Let's compare the Yamaha YZ125 with the KTM 125SX. There aren't many two-stroke 125s on the market, and given that the Husqvarna TC125 and KTM 125SX are the same motorcycle, there are even fewer of them.

So, the peak power value from the wheel. Yamaha YZ125 2021 produced 33.53 hp. Not impressive considering the 2021 KTM 125SX produced 37.5bhp. Fortunately, on the track it is not so far behind the KTM, especially since both motorcycles need to be revved up well to make maximum power. From idle to 7800 rpm, the Yamaha produces more power, and from 7900 to peak at 11500, the KTM 125SX outperforms the YZ125 by 2 and a half horses. Bottom line, the YZ125 is excellent up to 8000, and the KTM is excellent beyond that point. The Yamaha YZ125 spins up quickly, but at a certain point it runs out of steam, while the KTM is just waking up at that moment.

Yamaha YZ125

Motorcycle performance

The Yamaha yz 125 motorcycle has impressive technical characteristics that are worth considering in more detail:

To begin with, it is necessary to note the small dimensions, as well as the light weight of the motorcycle, which provide the model with greater maneuverability, agility, and ideal cornering. The soft suspension allows you to reduce vibrations even when driving on bad roads and bumps. Reliable disc brakes will give even novice drivers confidence when driving.

The powerful 2-stroke engine is capable of delivering more than 100 km/h to the driver, which will also please many motorcyclists. One of the biggest disadvantages of the motorcycle is its small fuel tank , as well as significant gas consumption. Thus, long trips or long distances are not suitable for the model.

Yamaha YZ125. Porting

Boring the cylinder windows will give more power, but it is better, in addition to boring, to also increase the compression ratio. In this case, you will have to ride on a racing mixture, which costs a lot of money, but the Yamaha YZ125 will ride much better.

There is one more nuance: simply sawing the window wider will not be enough; you will have to select the material for the cylinder base to make the windows lower, and then saw the head to match the piston stroke. If you don't lower the cylinder and don't saw the head, then don't waste time and money sawing windows.

Cons of Yamaha YZ125X

It's hard to have anything negative to say about this bike, but we do have a few criticisms. The first is that there is no electric starter. This sounds a little hypocritical - I just said how easy and convenient it is to start a motorcycle. Adding a push button starter will add weight to the bike, but it's a very handy feature. Secondly, the X has no protection - it would be nice to install engine protection. And thirdly, I would like the Yamaha YZ125X, as an "X" (not WR) model, to be more sporty. Compared to the YZ250FX, YZ450FX and YZ250X, the Yamaha YZ125X has much softer suspension settings.

Yamaha YZ125X 2020

Yamaha YZ125 exhaust

A regular Yamaha YZ125 exhaust from Pro Circuit, FMF, HGS or Scalvini will add about 2hp. But not all emissions are created equal. For example, take two Pro Circuit exhaust tracts. The first, standard, is the most popular option for the Yamaha YZ125. It's much better than stock, especially at high rpms. On a big, fast track, all riders prefer the stock Pro Circuit over the stock exhaust.

And the second Pro Circuit is a special version for the YZ125RV, named after Ryan Villopoto, who won races at the AMA National 125 All-Star with this exhaust. The YZ125R's exhaust is much stronger in the low end and midrange. The bike with it is not as smooth and torquey as with the basic Pro Circuit, but it goes great in clayey mud, on narrow trails, explodes sharply and shoots out of corners beautifully.

Reliability of Yamaha YZ125

The most unreliable components of the Yamaha YZ125 are the steering column bearings, front wheel wheel bearings, power valve and spark plug.

The steering column bearings are not sealed enough, so it is very advisable to fill them thoroughly with thick water-repellent grease and repeat this every six months. Otherwise, over time, the steering column axis will begin to move, and this will not go away on its own. Yes, and you just need to fill the lubricant - from a grease nipple, or if you find thick lubricant in the form of a spray. And make sure that the jet of a high-pressure washer does not enter the area of ​​the steering column, not only from above, but also from below, reflecting from the wing.

The front wheel bearings are another area where you don't want to spray the washer. Changing them is easy enough, but you definitely don't want to do it somewhere at a race. Therefore, do this periodically during regular maintenance; bearings are a cheap item. Try to get by when removing and installing them without a hammer, just using heat - but don’t overheat, especially when installing new ones. And don’t expect that they have enough lubricant from the factory: the most hardcore mechanics even wash the bearings of factory lubricant and fill them with their own, and to the maximum.

A power valve is a fairly reliable unit , but in the exhaust tract of a two-stroke vehicle, even an extremely reliable mechanical element will clog over time. When changing the piston, remove the power valve and clean it.

The spark plug in modern four-stroke engines is not as critical as in two-stroke engines. Two-stroke engines are extremely sensitive to a high-quality spark, cleanliness of the spark plug and correct clearance. For maximum reliable operation, use iridium spark plugs and change them as often as possible.

Yamaha YZ125

Jets

Over the course of 13 years, Yamaha has achieved the perfect mixture—as long as the engine is stock. It works cleanly and starts with one click. For a ported engine, with a higher compression ratio, with a tuned exhaust or with a crazy rider, there are racing blends. You can save a little money by mixing them half and half with gasoline. The motorcycle comes with two main jets - a richer one (440th) and a poorer one (420th). The current 6BFY43-3 needle produces a mixture half a notch richer than the old 6BFY42-3 used before 2011. Don’t be afraid to install a 440 jet and a slightly leaner needle. Experiment - that’s what replacement carburetor elements are for.

Specifications

The basis of the structure is a semi-double steel frame. Main geometric dimensions: length - 2139mm; width-827mm; height - 1318mm. For confident off-road driving, a ground clearance of 388 mm has been created. When equipped, the weight of the motorcycle is 94 kg. Gas tank capacity is 8 liters.

The required power is provided by a progressive single-cylinder engine. The working part of the cylinder is 124 cc. The fuel supply system is carburetor. Carburetor model: Mikuni TMX38. The operation of the main power unit is ensured by a liquid cooling system. Electronic ignition is installed, the type of which is CDI. You can start the engine using a kick starter.

For better passage of barriers and obstacles, a manual gearbox is provided, the number of gears is 6. The main gear is a metal chain. Front and rear tire sizes: 80/100-21 51M and 100/90-19 57M. A cross-class motorcycle must have a sensitive suspension. The front of the motorcycle has an inverted telescopic fork. Its stroke is 300mm. At the rear of the motorcycle, a pendulum suspension with a monoshock absorber (travel 245 mm) is used. The brake mechanism consists of front and rear brake discs.

Yamaha YZ125 Competitors

As I already mentioned, the Yamaha YZ125 doesn’t have much competition. The KTM 125SX is about $700 more expensive, but has stronger brakes, better steering, a hydraulic clutch, a better gearbox, more power, and a chrome-moly frame. For $700, a YZ125 cannot be brought to KTM condition - the clutch alone will cost almost twice as much, not to mention tuning to remove a comparable number of horses. But the advantage of the Yamaha YZ125 2021 is that for the money it is very balanced and does not have any frankly unsuccessful components that need urgent replacement after purchase. If you can't wait to invest some money in it, invest it in the engine.

Yamaha YZ125X In the forest

Yamaha YZ125X 2020

Engine

Of all the 125 motocross bikes I've ridden (TM, KTM, Husqvarna and Yamaha), the Yamaha YZ125X has the widest powerband and is the easiest to ride. However, it does not have the same amount of maximum horsepower as other classmates. When we first tried the 125X on a forest path, peak power was the last thing on my mind—we were faced with a slippery, muddy, narrow trail that required maximum control. And the character of the YZ125X engine was just right.

The power of the Yamaha YZ125X engine is even more spread out and linear than that of the YZ125 engine, and this allows you to ride in second gear where a regular 125 would not. Obviously, changes to the engine have shifted the torque peak down, which allows you to ride confidently in second gear. and avoid trees in S-turns and don't overuse the clutch.

I can't even say that I lacked mid-range power. The engine's character is definitely more four-stroke and linear, which makes the mid-range dip less obvious. That being said, you still need to shift a lot more often than 250F, and you need to be aware of what gear you're currently in.

Yamaha YZ125X suspension

It's probably the most comfortable suspension I've ever ridden, but it's a little too soft for me. This is not surprising, I am heavier (98 kilograms) than the rider the Yamaha YZ125X is aimed at. But with the sag adjusted for me, the bike felt well balanced. I could accurately predict how the front or rear wheel would behave when going over ruts, logs, roots, etc. The suspension is very soft, and still has pretty good resistance to hard impacts. It matches the power of the bike really well.

On the other hand, this is the only X model in the line that I don't think will be any fun on the dirt track due to the suspension setup.

Yamaha YZ125X 2020

Handling Yamaha YZ125X

The Yamaha YZ125X is so light and nimble that I had no problems on forest paths. This is a bike that handles like magic if you need to get through trees and roots. We spend a lot of time on four-stroke motorcycles and forget that two-strokes have much less mass of rotating parts and require much less rider effort to make the bike turn and change direction. Plus, picking up the bike (I've fallen a few times) isn't that hard.