「Recommendation」The Pipes in the Tank of the Surprisingly Good “ZXR250” are not for Show!

The ZX-25R's predecessor is an awesome racer replica

Introduced here is the Kawasaki ZXR250.This model, which appeared in 1989 at the end of the replica boom, was a replica machine that left a strong impression with its 250cc liquid-cooled four-cylinder engine from Kawasaki and the pipes protruding from the tank. It is a well-known model for those who love sports motorcycles, so it is not a minor motorcycle, but it was discontinued in 1999, more than 20 years ago, so it is unfamiliar to those who have recently become interested in motorcycles. Some people may think that a replica is not a big deal because it is an old motorcycle.

However, as its name suggests, the ZXR250 is the ancestor of the ZX-25R, the only 250cc four-cylinder super sport motorcycle on the new car market that is currently very popular. And just as the ZX-25R, released in 2020, had a powerful impact on the market that had never been seen before, the ZXR250 was a tremendous model that was the best of the high mechatronics of the time. However, when the ZXR250 was launched, it coincided with the end of the racer replica boom. Somehow, the explosive popularity of the Zephyr, released in the same year, transformed the motorcycle industry from a sports-oriented value system to one in which naked and street models took center stage.

In this issue, we will check out the charm of the ZXR250, which has been fighting well for nearly a decade in the midst of such a market swell and has succeeded to its name in the latest modern model.

The ZXR250, released in 1989, was the first liquid-cooled four-cylinder model in the 250 cc class, which until then had been dominated by two-cylinder models. It was also the first model in its class to feature inverted forks and unique systems such as "K-CAS" and "K-RAS," and boasted a competitive edge over rival racer-replica models.

Will you go that far!? All-out high mech.

This time, only one company, Kawasaki, sells this 250cc inline four-cylinder model. In 1989, however, it was a very luxurious time, when all four major Japanese manufacturers had these models in their lineups.
Of course, each company also introduced cooperative models in full-cowl racer replicas, combining their technological strengths.
The GSX-R250R from Suzuki, the FZR250R from Yamaha, and the CBR250R (MC19) from Honda were all equipped with super high-revving engines that were just short of the voluntary output limit of 45 PS at the time. The endurance racer-like dual headlights were used to compete with the two-stroke replicas that raged at the time.

Under such circumstances, Kawasaki's 250cc sports model lineup is dominated by the two-cylinder GPZ and GPX series.
Even before this, Kawasaki had always pursued a unique focus on two-cylinder engines, and that is why the company never stopped manufacturing two-cylinder models. As expected, rival manufacturers were going all out to introduce four-cylinder models, and the ZXR250 finally made its appearance.

The ZRX250 was born against this backdrop. The engine, newly designed for this model, delivers 45 PS at 15,000 rpm, which rivals its rivals. The body is an aluminum twin-spar "e-box frame," and the suspension features inverted forks, the first in its class. The body is built on an aluminum twin-spar "e-BOX frame," and the suspension features an inverted fork, the first in its class. These are impressive specs when viewed from today's perspective.

Kawasaki's first 250cc liquid-cooled four-cylinder engine boasted a side cam chain layout and ultra-high rpm.
The output of the early model was 45 PS at 15,500 rpm, which was just under the voluntary regulation of the time.

From the left, the speedometer, tachometer, and balance meter. The style of placing the tachometer in the most prominent position is a layout common to racer replicas of the time. The upper limit of the tachometer is 20,000 rpm, which is a very high rpm.

Double disc brakes are used on the front wheels. Following the engine, an inverted fork was adopted for the first time in its class. This is a common feature on sports models today, but at the time, it was the first of its kind for high mechatronics.

The tank is large, with a capacity of 15 liters, making touring no problem. The pipe extending through the upper cowl is a major feature unique to the ZXR.

During the motorcycle boom of the time, it was common for popular models to undergo model changes at an impressive pace. The ZXR250 was no exception and underwent a major model change in 1991. The ZXR250 was no exception and underwent a major model change in 1991. The new twin headlights with a single-lens design gave it a different appearance, but the engine was also improved in various areas, with peak output peaking at 16,000 rpm.

The model was remodeled in 1991, with an improved engine and new styling. The model in the photo is from 1994, and its single-lens twin headlights are a major feature of its appearance.

What is that pipe you are interested in?

Although the ZXR250 boasts such high specifications, there is one point that is odd from a modern perspective: the two hoses protruding above the tank. That is the two hoses protruding from the top of the tank. These pipes, which are made of aluminum for the early twin-lens type models and of resin for the later models, are connected to a hole in the cowl above the headlight, through which they penetrate the tank. It is open above the cylinder head. Because of its odd style, it is sometimes called a zerk pipe or a wash hose.

This is a unique feature of the ZXR series called "K-CAS," a part of a function that draws clean, cool air in from the front of the cowl and applies it to the hot cylinder head for cooling. K-CAS" is an abbreviation for "Kawasaki Cool Air System.
The name is a bit dated, but in reality, it is nothing more than a hollow pipe, and some riders have even removed it.
However, there is no doubt that it is a major design identity.

The K-CAS hose defines the appearance of the ZXR250. It runs from the upper cowl through the tank and cools the cylinder head. Incidentally, this pipe can still be purchased as a genuine Kawasaki part (as of 2022/09).

This part is also often mistaken for the Ram Air System. The Ram Air System is a system that directs fresh air to the intake system leading to the carburetor, which Kawasaki also named K-RAS, but in the case of the Kawasaki Ram Air System ZXR250, its intake is located under the side cowl and has a different path than the pipe.

The intake of the ram air system, which is often misunderstood, is located in the middle of the under-cowl. This system sends the running wind directly to the air cleaner by utilizing pressure.

In other words, surprisingly good ZXR250.

The ZXR250, which exhibited such high mechanical performance and high potential, was never an unpopular model, as I mentioned at the beginning of this article. However, because the period in which it was active unfortunately coincided with the end of the replica boom, a derivative model of the ZXR250 has become more famous today, which is unfortunate, because that derivative model was the Barrios, which even today boasts popularity as the leading 250cc inline 4-cylinder naked model. The engine of the Barrios was a 250cc inline four-cylinder engine. The engine of the Barrios is based on that of the ZXR250. This made it a model with super high-revving engine performance that did not match its classical appearance. However, there are still many riders who were attracted by its high performance backed by its high mech.

In other words, the ZXR250 is:

- The last generation of racer replicas, with the ability to compete with its rivals.

It was a surprisingly good motorcycle. The ZXR250 was discontinued in 1999, but people who knew the old ZXR250 were surprised to see the model number of the ZX-25R that appeared in 2000. The ZXR series had ended with the ZX250D model, but the ZX-25R model is very different from the ZX250E mechanism, but it is the ZXR250 that has been revived after 11 years.

ZXR250 (1991) Specifications

Photo cooperation: Red Baron

Check out the ZXR250 user reviews.

Click here to read ZXR250 user reviews. **JP Website