Detail of European Model "YZF-R6"

2003 European model Yamaha Sport "YZF-R6"
Name:
Yamaha Sport "YZF-R6"
Release date:
December 2002(varies with European sales companies)

Yamaha Motor Co., Ltd. will unveil the 2003 European model Yamaha Sport "YZF-R6" at the "Intermot Munich 2002" (3rd international motorcycle and scooter show) to be Munich, Germany for five days starting September 18. (Press introduction day is Sept. 17th.) This will be the first production model to feature parts cast by the new Yamaha "CF Aluminum Die casting Technology." After its debut at the Intermot show in September of 1998, the original YZF-R6 quickly won acclaim in Europe as "a supersport machine that offers full enjoyment of 600cc power" and became the new standard in the mid-class supersport category. The 2003 model represents first model change of the YZF-R6 in four years and was developed around the same original model concept while adding further refinement of cornering performance and even more exciting engine performance. The main changes in the new YZF-R6 include, (1) a new engine comprised of about 90% new parts, (2) fuel injection, (3) meets EU2 emissions standards, (4) first production motorcycle frame made exclusively of cast parts, (5) chassis parts made by Yamaha's new CF Aluminum Die Casting Technology rear frame and rear arm) and (6) styling that tells you at a glance this is the 2nd-generation YZF-R6.

Engine
1) New engine with 90% new parts including new-design pistons

The new YZF-R6 adopts a new liquid-cooled 4-stroke DOHC in-line 4-cylinder 4-valve engine with about 90% new parts including new forged pistons designed for optimum strength balance, new high-lift cams and a redesigned crank case. While maintaining the outstanding character of the existing engine based on the bore x stroke dimensions, compression ratio and the combustion chamber shape, the new engine is characterized by boosted performance across the full rpm range due to improvements such as optimized intake/exhaust efficiency and measures to reduce pumping-related horsepower loss. As a result, a power increase of about 3 hp has been achieved while maintaining the same maximum power output rpm of 13,000 rpm (while ram-air intake is in effect)

2) Liner-less direct plated cylinder

In order to reduce the resistance of the piston in motion, a new type of cylinder has been adopted which eliminates the cylinder sleeve and applies plating directly to the inner wall of a die-cast cylinder for what is called a "direct-plated cylinder." Elimination of the sleeve enables outstanding heat dissipation characteristics, good strength balance and a more precise cylinder design. What's more, increasing the strength of the land that holds the rings, optimizing the thickness of the top ring and revising the ring tension all contribute to more stable piston movement. All this helped in achieving a more consistent gas seal and excellent oil-consumption characteristics. Furthermore, the new crankcase design with enlarged passages between the cylinders reduces fluctuation in air volume due to the pumping action of the pistons, thus reducing pumping-related horsepower loss. This helps produce to outstanding response characteristics. Horsepower loss has also been reduced by various design measures like optimizing the crank balance to reduce the load on the crank journal.

3) Fuel Injection system with suction piston

In order to obtain both outstanding intake efficiency and good response, this model adopts the same suction-piston type fuel injection (FI) system that has won such high acclaim on the 2002 model YZF-R1. This system uses the motion of a free piston that moves in accordance with the air pressure fluctuations to regulate air intake flow from the low-speed range, thus making possible both linear throttle response that retains a natural (carburetor-like) intake feeling and the outstanding response and reliability of electronic control. This enables the new YZF-R6 to achieve acceleration characterized by a second acceleration curve beginning at 8,000 rpm and excellent top end power development that continues without stress past 12,000 rpm.

4) New-design intake system

To improve engine response in conjunction with the adoption of the new FI system, the air cleaner capacity has been increased (7.3 → 7.6 liters) along with the diameter of the throttle body (37 → 38 mm). The same "ram-air system" used on the existing model is adopted, and to accommodate the new FI system, the volumes of the intake air passages at the open and closed states have been optimized to produce even better perfor

5) New-design titanium muffler

New-design titanium mufflerThe exhaust system has also been completely re-designed for improved performance and weight reduction. The previous two-section interior structure of the diffuser has been replaced by a single-unit titanium structure. The double-layer tube structure with glass wool stuffed in between the two layers is given a curved shape that provides both outstanding exhaust efficiency and reduced noise. In addition, a lightweight aluminum outer cover for the silencer has been adopted along with other changes including an increased overall size for the exhaust system, new pipe length dimensions and joint position, new silencer expansion chamber ratio and changes in the sizes of the various tubing, all designed to bring out the new engine characteristics to the fullest. All in all, this new exhaust unit is a full kilogram lighter that the existing unit even when the weight of the new catalyzer element is added.

6) Other changes

Other changes include (1) clearing EU2 emissions standards, (2) optimization of the shape of the crankcase cover to improve oil return, (3) adoption of a lightweight aluminum oil cooler, (4) weight reduction through the use of plastic for some internal engine parts, (5) rare-earth element magneto adopted for a thinner ACM, (6) revision of shift rigidity and change in shift revolving mass and (7) adoption of a round radiator with excellent cooling performance with no increase in size compared to the previous unit.