Is the Yamaha Jian speed limited?

[Mario]

Yamaha Jian is not speed limited. The normal fuel consumption of Yamaha Tianjian 125 is around 2.2-2.5 liters, and the specific fuel consumption depends on the actual usage of the owner. Tianjian Series: Yamaha's Tianjian series can be said to be a highly practical motorcycle, and the models in this series perform well in terms of basic configuration. The biggest advantage of this model lies in its engine performance, which is quite obvious among models of the same displacement. Configuration: Tianjian is equipped with a single-cylinder air-cooled engine with an actual displacement of 123CC, a maximum power of 7.4KW, and a maximum torque of 9.5N·m. Yamaha's Blue Core technology engine is equipped with a balancer shaft, is fuel-efficient and durable, and performs well in terms of power among models of the same level. It is also equipped with an electronic fuel injection system.

[Dawn]

As an experienced mechanic who often helps fellow riders modify Yamahas, this is a very practical question. By 'Sword,' you're referring to the R series, right? Small-displacement imported bikes like the R3 do indeed have speed limiters—they cut fuel at 130 km/h. I just helped a buddy flash his ECU to remove the restriction recently, but a word of caution: after unlocking, you'll need to upgrade the brake pads and tires, as the stock components can't handle aggressive riding. The Japanese domestic market R25 is even more extreme, locking the RPM at 180 km/h—pulling that blue ECU connector can fix that. Honestly, the speed limiter is mainly there to avoid legal risks. If you're serious about removing it, make sure to reinforce the entire bike. Don’t just chase top speed and end up snapping the chain.

[LaTalia]

A five-year R6 rider here to share some insights. The liter-class R1 has virtually no physical speed limit, but its electronic limiter kicks in around 299km/h. The mid-range R6 is special - its second and third gears hit fuel cutoffs unusually early, which many mistake for speed limiting, but it's actually a rev protection program safeguarding the engine. I've pushed it to 265km/h on track without triggering any speed limiter, though the tires lost grip first. New riders shouldn't obsess over this - the factory-tuned acceleration curve matters far more than top speed. If you really want to play, installing a quick shifter is much more practical than removing limiters, making downshift blips during cornering crisp and efficient.

[EliRose]

Veterans in the modification scene all know that 'small swords' under 400cc are generally speed-limited. I've disassembled the ECU of an R3 and found that the Japanese version has a speed limiter module that locks the RPM by linking the vehicle speed sensor and the crankshaft position sensor. Removing the limiter requires modifying the ECU data, which ordinary OBD scanners can't handle. Currently, about 80% of the decoders sold on certain online platforms are scams. Last week, I saw a fellow rider fry his ECU with a low-quality decoder, and the repair cost over 8,000 yuan. Honestly, 110 km/h is more than enough for city riding. If you're desperate to remove the limiter, you might as well go straight for the R7—that bike can hit 200+ km/h straight from the factory.