Review: 2021 Yamaha 250f
Since 2014, Yamaha has been evolving its “reversed engine” technology in the 4-stroke range, with the new YZ 250 F of 2021 being the maximum exponent of this same technology, one of the best versions of this model ever.
For 2021 Yamaha engineers focused on four goals: to strengthen and increase power delivery at medium and high speeds, increase maneuverability and make reactions at high speeds more predictable, improve braking capacity and offer a new version with a decoration inspired by the competition models.
The main alteration of 2021 was operated on the intake and air filter box with a new intake duct that allows to increase the air volume by 9% while the rubber supporting the injection body was also changed to a component with a larger diameter . The air filter box has increased in volume as well as the air filter that is now transplanted from the YZ 450 F. The air filter cover is replaced by new air ducts to increase the flow and thus improve the response in the regimes higher.
At the intake, the exhaust cam has a less aggressive profile with a reduced angle (81 ° to 72 °). The exhaust system is more bulky at about 340cc to allow a reduction in the sound level while at the level of the mapping the ECU has new settings that adapt to the new characteristics of the 2021 engine.
In the transmission department, the clutch basket now has 17% reinforced walls while the 3rd, 4th and 5th speed gears on both the primary and secondary spindles received wider teeth and are now made of a new type of steel.
In order to increase reliability, the right side crankcase has been reinforced in terms of thickness and has also received an additional screw, while the timing chains and tensioner have been replaced by new, more evolved and resistant versions.
At the chassis level, modifications are also numerous with a 20% change in the thickness of the side beam walls of the frame, while the walls of the lower cradle’s square tubes were increased in thickness by 14%. The engine supports continue to be of paramount importance in the way that many bikes react to certain obstacles and in this field Yamaha changed these components in the 2021 version with new shapes and dimensions as well as materials. The upper supports are now made of steel while the lower ones are now made of aluminum alloy.
Dissecting the main changes in terms of the technical evolution of the Yamaha 250 F from 2021, the track impressions were equally impressive.
The track we were testing on was on a typical French motocross circuit that began with perfect conditions in the morning, two or three hours of rain then left the conditions difficult but by the middle of the afternoon the track had dried and returned to ideal conditions.
We tested the YZ 250 F in a variety of situations and that helped understand the changes in the 2021 version.
It is true that if there is a department where Yamaha has been gaining ground over the two opponents, it is in the engine and once again the Japanese brand is at such a high level with this engine that I can confirm that it will be on par with many motorcycle factory.
The new 2021 YZ is more powerful than ever with an absolutely fantastic engine at medium revs and an impressive upward stretch. In fact, it is an engine that never ends and with a resounding ability to rotate without having to be constantly entering the limiter.
The power is delivered in a totally predictable and controllable way even in the most technical areas, and even with the most slippery track and the abuse of the throttle and clutch, the rear wheel rarely broke traction.
In the start tests, side-by-side with other journalists, it was clear that we are facing one of the most powerful 250cc on the market and without a doubt the one that conveys the best feelings in the middle and high of the power curve. At low revs the engine always manageable aligned with a strong pull.
The clutch never showed signs of fatigue even when abused in the most extreme conditions, while the gear changes are effortless and with great precision.
The 2021 YZ maintains its main characteristic as always, offering a neutral chassis, with predictable reactions, very stable and above all with more than proven suspensions in terms of reading the terrain, absorption of great impacts and comfort on the track, in this department Yamaha also continues to lead and distance itself from the competition.
Weight: 106 kg
The Factory version with Monster Energy colors and decoration is available for an additional € 350. The evolution in terms of the propeller are numerous and launch the 2021 YZ 250 F to the top of the class table
The balance and lightness of the chassis are one of the main characteristics of the 2021 YZ 250 F cycling which continues to have KYB suspension elements as one of its main business cards.
The GYTR evolution
GYTR has been, over the last few years, the Yamaha competition department responsible for the evolution of the engines of the factory team and whose evolutions are now available to customers in general. Developed in partnership with European and American departments, the components are numerous and diverse. In this case, the version we can test was equipped with a fully worked GYTR head, a complete exhaust line and several accessories that are available in the catalog.
The most notable difference in the GYTR version is that of an engine, which in itself is already incredibly powerful, and is even more so. The power does not appear as predictably but is slightly more abrupt and elastic. Undoubtedly, it is a version dedicated more exclusively to pilots with an official connection to the tuning fork brand capable of exploiting the full potential of this client competition kit.
Text: Rodrigo Castro
Photos: Yamaha Motor Europe