Yamaha XS 650

Yamaha XS 650 was the first motorcycle engines with four-stroke engine from Yamaha. Motorcycle models in this series were built in different series from 1969 to 1984.

Model history

The first model of Yamaha XS 650 series was presented by Yamaha from October 24 to November 6, 1969 at the Tokyo Motor Show with the type XS1. The sale and the model properties were initially disappointing; of the first type, a total of 6586 pieces were manufactured; the result type XS2 reached 18,283 units. The sale of the XS2 in Germany for 1971 was 153 and for 1972 only 192 motorcycles. Mitsui Machinery GmbH ( Germany Yamaha ) Then took the machines ( XS2) from the German market; abroad the altered XS2 was sold under the name TX 650/TX650A on. As an interim solution, the Yamaha TX 750 was offered. After major overhauls the XS was 650 series from the introduction of the II generation ( model year 1974/1975 with XS 650 ( B)) marketed successfully. From 1977 Chopper models were also offered, which were characterized by the addition of " Special". In 1978, the first 97 copies ( XS 650 Special) were of the French importer Sonauto imported by air freight. Not all versions arrived in Germany officially for delivery. However, there were a number of other imports to Germany. The last models were produced in 1983 and were partially available in new vehicles by 1987.

Framework development

The scope of the series XS 650 was from the beginning a double -cradle frame, in which the engine is installed as a reinforcing element. The properties of the XS1 - frame improved Yamaha in honing, by the British Percy Tait (formerly of development and racing division of Triumph) and projects such as the Yamaha XS 650 Special NVT (Norton Villiers Triumph).

For some modifications based on the XS 650 Special frame were manufactured. Sources were, among others AME Chopper Products ™, Wasp ( enduro sidecars ), Fiedler ( chopper frame) and more custom. The base frame of the XS 650 has been used internationally for sidecar racing and road use. Kenny Roberts sr. In 1973 and 1974 Dirt Track World Champion on Yamaha XS with shell chassis and Spanish 35mm Betor fork. After the ABE- No. 9623 of Automotive Federal Office of 20 May 1975 was given no aptitude for team operation. The corresponding ABE was deleted 8 July 1985. There are known several other reports.

The scope of the series have been amended several times and always reinforced with the introduction of the second generation. By the end of production with the code 447, the " Europe " frame differed to the other frame. The European framework had an additional cross tube and frame reinforcements between the two beams in front of the engine block. Note the changes in the dimensions of the steering geometry.

Engine and transmission development

The basic concept of the engine is a four stroke engine with gleichläufigem parallel twin, which reveals similarities with the developments of Horex in origin, but Ludy E. Beumer, Yamaha Motor Europe NV denied. The relationship of the motor is based on a novel at the time camshaft drive by Hermann Reeb ( Horex Columbus ). (See Patent Information No. DE- 893 875 ). First, the motor for the Horex Imperator 500 was developed, but was only reduced in the Horex Imperator 400 for use in the series. The company Hosk in Japan then built these engines under license. Hosk was acquired by Showa and the motor to a version with 650 cc developed. Later Showa was acquired by Yamaha and so this engine was the basis for the model series XS 650 available. (Yamaha followed with this approach to the scheme, with the successful Kawasaki Kawasaki motorcycles W-Series was introduced. , The manufacturer acquired from Meguro Kawasaki manufactured under license parallel twin engines of the British motorcycle manufacturer BSA. ). More development objective was the use of technologies, the 2000 GT were developed by the Yamaha engine of the Toyota. From 1989 to 2002 Yamaha built for the Yamaha TRX models (850 and 900 cc ), Yamaha TDM (850 and 900 cc ) and Yamaha XTZ 750 more engines with parallel twin. Since 2006, Rotax and contact the BMW engine BMW F 800 an enhanced version of a parallel twins.

A special feature of the Motor-/Getriebeblocks time was the introduction of horizontal split assemblies. Until then, a vertically split casing was common in these engines. Reasons for the horizontal division were the simplified production and less oil loss. The first fundamental change to the gearbox and the case came with the introduction of the electric starter. The clutch has been modified more than once in order to be adapted to the torque. Likewise, further reinforced components were offered for use with uprated engines. From the field of motorsport engines of this series up to 1000 cc are known. ( Victory in the European Cross - Gepann Championship 1975 by Ton van Heugten with XS 650)

The built- in engine block alternator was exposed by design the vibrations of the crankshaft. The power of the generator was increased in several ways:

The performance, the replacement costs and the durability of the alternator were frequent point of criticism. Therefore, multiple -independent solutions have been developed by owners of these machines.

Carburetor variants

Already the first model XS1 was equipped with two Mikuni BS -38 carbs. The development of these vacuum carburetor goes back to a licensed production of Solexvergasern. With the introduction of soft chopper some smaller carburetor type Mikuni BS 34 were installed. These carburetors were subjected in the course of development and numerous changes were screwed usually one couple. For later model versions, which possessed a vacuum-operated petcock, a connection has been integrated in the suction flange.

Ignition

Most of the models were compared with two breaker contacts (saves the distributor ) for the battery ignition and a mechanical ( centrifugal force- controlled ) spark advance delivered. Later models such as the XS 650 G Special ( Code 3G0 ) have an electronic ignition system. Furthermore, light barriers were controlled in the aftermarket, electronic ignitions ( Piranha type ) offered that were shared with the mechanical ignition timing. Also often a conversion to electronic ignition Boyer was made that needed no mechanical components to the ignition timing.

Model History

The model history of this series is characterized by extensive facelift and several country versions. There were consummated fundamental changes in engine, frame and other equipment over time. An overview of this is the following table of the model series, but again are only a few details of changes. 27 ° / 115 mm, wheelbase: From the introduction of the second generation, a modified Tait ( reinforced ) frame with the chassis dimensions Caster / Trail was 1435 (later model year 77/78 Steering Head / Trail: 27 ° 45 '/ 119 mm used). Further deviations to each are shown in the table. The suffix " S" each featuring models with alloy cast wheels. The following data are taken from the model overview listed in the links.

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