Type to search

FEATURES TRACK TESTED

2020 Yamaha YZ250F | Track Tested

Share

2020 Yamaha YZ250F | Track Tested

Few modern-day motorcycles have a history like the Yamaha YZ250F. Debuted in the early 2000s, it was the very first four-stroke motocross machine of its displacement and it immediately indicated that the two-stroke 125cc reign was near the end. Yamaha refined the machine through the early years with new frames and engine designs, but not at the pace other OEMs, and by 2011, the outdated carbureted engine and aluminum frame were among the least liked in the division. That all changed in 2014, when Yamaha started with a clean slate and dropped a more powerful fuel-injected powerplant into a reconfigured chassis and again became a leader in the 250 class. In 2019, the YZ250F received a big makeover and the result was the hands-down winner of the majority of media shootouts last year.  That said, the 2020 bike returns basically unchanged, save for a set of new in-molded graphics in the radiator shroud. But is that a bad thing? Hell no!

What’s New

Instead of being smart asses and just writing about the cool new silver highlights in the graphics, we’ll review what was all-new in 2019. Like every other Japanese OEM, Yamaha remained with aluminum as their material of choice for the chassis, but the dimensions and construction of the bilateral beam frame has been greatly changed. The tank rails of the ’19 and ’20 bikes are extruded aluminum and have a much straighter profile than before. The tension pipe, steering pipe, swingarm bracket forging, engine mounts, shock mount, cradle pipe, and fork lugs all changed from 2018 to 2019 through construction materials, dimensions, or placement, and together this creates a large triangle of energy absorption. With this configuration, the vertical, horizontal, and torsional rigidity of the chassis have all been increased and the flex characteristics have been made smoother.

In an effort to slim the rider cockpit area considerably, Yamaha also mounted the new radiators more vertically and 6mm closer to the frame and then narrowed the fuel tank and seat width by 16mm and 18mm, respectively. It must be noted that the change to the fuel tank has dropped the overall capacity from 1.9 gallons to 1.6 gallons, but the total volume is said to still be more than enough to finish a full 30-minute moto at pro rider speeds. Yamaha has replaced the multi-piece radiator shroud and airbox cover set up with a new smaller and less complex design that has been shaped to be slimmer near the frame and gradually open out around the radiators for improved rider movement, and the seat is now flatter and lower than before. Every piece of plastic, from the front fender to the rear fender, has been replaced with new components that offer sharper body lines and improved rider movement.

Yamaha aimed their efforts toward improving the mid- to top-end power characteristics of the engine, making the chassis nimbler on the track, and the overall layout of the bike easier for the rider to maneuver around. To coax more performance out of the engine, Yamaha refined the cylinder head to make it more efficient through a new intake camshaft, straighter and smoother intake and exhaust ports that increased flow rate, a new crown-shape piston with a higher compression ratio (from 13.5:1 to 13.8:1), a new valve train with larger lifter buckets and increased valve spring rates, dual-electrode spark plug, a change to a 44mm Mikuni throttle body with 12-hole injector, and an updated exhaust head pipe design. In addition to these changes to the cylinder head, Yamaha dropped in a new clutch that has a higher heat capacity through larger and thicker plates and six clutch springs that is matched to the transmission that is made from high-impact steel. The new ECU is con-nected to Yamaha’s innovative smartphone-based Power Tuner app that allows riders to alter the fuel and ignition mapping for track conditions or riding styles, while a handlebar-mounted system allows the rider to switch between two preloaded maps on the fly. All of this is brought to life with the electric starter that is connected to a 2.4Ah, lightweight lithium-ion battery. With the addition of the electric starter, Yamaha crafted new engine crankcases that feature a more upright cylinder in- cline and eliminated the housing and components for the traditional mechanical starter.

Suspension has never been a concern on the Yamaha YZF line, thanks to their use of KYB’s SSS mechanical fork and shock, but even those areas saw refinement for 2019. Hidden inside the fork tube are a 25mm cylinder and piston (up 1mm from 2018), a new mid-speed valve with leaf spring, a new pressure piston, and a stiffer spring rate of 4.7N/mm (up from 4.6N/mm). On the rear, the shock body’s sub-tank capacity has been increased by 30cc and is paired with a new spring that is made from thinner material and features less bends in its design for reduced weight (210 grams) and a stiffer spring rate of 56N/mm (up from 54N/mm). The changes to the fork cylinder and piston plus the shock body allow for an increase in oil flow for a more controlled damping character.

On The Track

It’s difficult to pinpoint what sticks out the most when riding the 2020 Yamaha YZ250F. Is it the power profile of the engine or the stiffer feel of the chassis? Both are apparent as soon as a rider gets going on the new blue bike, as together they entice a rider to push the pace and try new lines. We’re pleased to say that the multiple changes made to the engine in 2019 in an effort to increase mid to high did not sacrifice the low-end that the YZ250F has become known for, as the bike still pulls with power and has torque that is unmatched by other bikes in the class. But once up to speed, it’s clear that the engineer’s intentions were accomplished. The powerplant works best when revved and stretched out every gear to the maximum and as soon as they click up on the shifter, the speeds quickly increase. Our first motos were done with a stock map setting from Yamaha programmed into the ignition, and soon after we added a map developed in house by Yamaha test rider Travis Preston. Our impression of the bike was immediately changed for the better, as the engine revved freer and felt even faster. But with that said, everyone will be able to find a setting they feel suits them best through the ignition and fuel mapping adjustments offered through the Power Tuner application.

The chassis of the 2020 YZ250F is definitely suited for faster riders, as the increased rigidity feels incredibly stiff when compared to the 2018. But this is actually a good thing because it seems much more planted and predictable, which makes a rider more comfortable and confident as they push the pace. Straight-line stability is much improved, with no sensations of headshake or uncertainty when at speed. Yamaha’s decision to greatly angle the placement of the engine in the frame for an improved center of gravity has been met with mixed opinions over the years, but this current iteration is the best used so far in the YZ250F, because the front-end does not suffer from the vague steering sensations that so many have complained about. All of these attributes are greatly aided by the KYB suspension components, which are the best that have ever graced the small-bore blue bike in stock condition. The fork and shock absorb every impact with predictability and precision, without a harsh sensation anywhere in the stroke, and the increased spring rates are perfectly matched to the stiffer sensation of the chassis. All of this, plus the ease of use through the traditional tuning tasks (no fork pumps needed here) make it clear why Yamaha never strayed from the standard spring path.

To be blunt, the body panels of Yamaha’s previous machines were bulky, overly complicated to assemble, and made it difficult for a rider to move around. With that said, we’re pleased to see that they’ve ditched the old designs for slimmer, sleeker pieces and a smoother seat that never interferes with a rider’s movements. The flat and narrow compartment will appeal to riders of nearly every size and skillset, and the look is much more attractive. Most of our riders expressed no issue with the bend of Yamaha’s tapered handlebar and all applauded the adjustability offered by the bar mounts.

The 2020 Yamaha YZ250F may be the same bike that we had in 2019, but in all honesty, we don’t see why it needed anything more. Will the ’20 bike stand atop the heap when it comes 250 Shootout time? We wouldn’t bet against it.

Tags:
Donn Maeda

Donn Maeda is a 30-year veteran in moto-journalism, having worked at Cycle News and Dirt Rider before launching MXracer Magazine and TransWorld Motocross Magazine. Maeda is the Editor-In-Chief at Swapmoto Live and you can catch him on a dirt bike or in the saddle of a mountain bike on most days.

  • 1

You Might also Like