Yamaha SR 500

The Yamaha SR 500 is a motorcycle model of the Japanese manufacturer Yamaha, which was built from 1978 to 1999. In Japan, it is offered with a modified engine as SR 400 to today. The designation " SR " stands for " Single Road ".

History

The SR was derived as a street machine of the Enduro XT 500 which was marketed very successfully since 1976. As a large-volume single-cylinder, it follows the tradition of classic, especially English motorcycles, while the former trend was towards more powerful four-cylinder engines.

The robust and manageable technology and the large number of motorcycles sold meant that it comes to SR 500 is a keen supporter and club life today. There are numerous modifications as Cafe Racer, Scrambler, sidecars, bobber or chopper. Even in amateur racing, the model is often used.

2003 were registered in Germany for about 20,000 units, with a decreasing trend.

Type overview

There were the models 2J2 ( 1978-1979, for example the U.S. market ), 2J4 (1978-1983 Germany ) and 48T ( 1984-1999 ). In Japan, the model is sold to date (eg Black Edition 2008 30 -year anniversary ), for tax reasons but were ca 38 000 copies of the SR in Germany as SR 400 Between 1978 and 1999 sold ( and Others 1981 in West Germany 4,767 pieces) and was in spite of the 12-liter (from Autumn / Winter 1986 paint record change: 14 liters ) capacity apart fairly small tanks as a reliable tourer, from some peculiarities at startup behavior. In the years prior to the sale transmission but decreased the registrations. Most buyers expected an electric starter, and as a result of stricter noise and emissions regulations the engine power was reduced to 17 kW/18 kW. In model year 2014, the machine is again offered as SR 400 in Germany.

Technology

The engine of the SR 500 was based on the engine of the XT 500, a single-cylinder four -stroke with relatively high power at low speeds. Hence the nickname " Thumper " is derived from, which is about as much as " steam hammer " means in German. Through their interpretation as a short Huber and especially because of the two-valve technology, the maximum power of the SR is only on at speeds of about 6200 rpm, the maximum torque at 3500 rpm approx.

To adapt to the other application, the SR motor was compared to the XT including a contactless maintenance-free electronic ignition system and a 12 -volt power supply and more flywheel on the crankshaft. Compared to its sister model, the frame is also provided with reinforced pipes. A special feature is the dry sump lubrication, the oil reservoir is located in the upper frame tube.

48T models are different from the early versions, especially by the smaller front wheel and the wear-resistant engine got a modified oil supply to the cylinder head for thermally highly loaded exhaust valve and a gas-nitrided camshaft with optimized valve lift and hard block - rocker. The bike has an air-cooled 1 -cylinder 4-stroke OHC engine with 499 cc displacement, the (27 hp) was reduced for the German market because of that driving licenses and insurance classes to 20 kW. Unthrottled, with enlarged intake and the Model 48T with a different carburetor jet, making the engine 25 kW (34 hp).

At the end of production had the engine, due to stricter noise and emission regulations, only 17/18 kW ( 23/24 PS), unthrottled 20 kW (27 hp). A standard "newer" SR reaches a top speed of about 135 km / h and a SR 500 with 25 kW ( 34 hp ) 145 km / h In late 48T models the front disc brake for aesthetic reasons was replaced ajar a technically complicated and DS -7 ( predecessor of the RD -250) drum brake.

The SR 500 and SR 400 have no electric starter. Flipping with Kickstarter is facilitated by a valve lifter.