Yamaha Rz350

RZ350 (1984)

Yamaha RZ350 (RD350LCII) (liquid cooled) in some countries) is a motorcycle powered by a twin-cylinder two-stroke engine, reed valved 347 cubic centimeter engine. The bore and stroke are 64x54 mm. It produces 30.4 ft·lbf (41.2 N·m) of torque at 7500 rpm. Coming out in 1983, it was the evolution of Yamaha's popular and well known RD350 (1972–75) and RD350LC (1980–86). Production was carried on into the 1990s and a different version with no YPVS power valve in the engine was used in Yamaha's Banshee ATV until its final model year in 2006 in the United States. Yamaha Motor sold the Banshee in Canada until 2008. There were several other models, the 1985 RZ350F, 1986-92 RZ350F2,N,NF, and the 1992-5 RZ350RR was produced in Brazil.

RZ350 is now a sought after collectors motorcycle in America, and its association with world famous three-time GP champion Kenny Roberts, as it was sold exclusively in the USA as a signature model. It is also raced extensively in Vintage racing leagues, as well as its own racing leagues, often dubbed "RZ cups" in Europe.

Versions

This bike was only sold in the United States for two years 1984-85. In the USA it came with catalytic converters for emissions requirements, and was the first motorcycle to do so. It was only sold in California in 1985, as the RZ350NC, and a second version was sold in late 1985-86 as the RZ350NC2, both of which had an EVAP canister and an additional catalytic converter in the exhaust pipe header to meet California emission regulations. It was not sold to the public after because Yamaha decided it would cut too far into their emissions quota mandated by the United States Environmental Protection Agency and limit sales of other larger displacement bikes which were more popular sellers. The RZ350 was also the first Yamaha street bike sold in the USA that used a "perimeter" frame as opposed to the standard frames of the era which ran under the center of the tank.

Styling

The two 1984 USA models were yellow and black (Kenny Roberts Special) and a sparkle red-white and blue model that had different graphics and no Kenny Roberts signature on the upper cowl. In 1985, the red-white-and blue versions had identical graphics to the yellow and black "bumble bee" Kenny Roberts version, complete with signature, but they had a red frame. There were also the leftover models with revised graphics that somewhat resembled the 1983 UK versions, but had gold rims and a Kenny Roberts signature, that were sold as RZ350NC2 in California only from late 1985-6. Estimated RZ350 production for the USA is about 20,000 motorcycles.

The RZ350 had a variable exhaust port valve called the Yamaha Power Valve System (YPVS) that was controlled by a basic computer. The YPVS could adjust the height of the exhaust port and thus affect the exhaust port timing. This provided lower RPM torque while retaining high RPM power. Many of these bikes were salvaged because of the interchangeability of many of the major engine components with the Banshee ATV. There was a 500 cc version called the RZ500. It came in a red-on-white color scheme. It was a twin-crank V4 version (much like the GP bikes of the era) and was a quite different bike. Some distributors and dealers sold these bikes with custom paint jobs, causing confusion about OEM paint schemes.

In many countries, these bikes were known as RDs, but in North America and Australia they were called the RZs.

Note: in Australia, England, Canada, and the USA the Yamaha RD series (RD125,RD250,RD350,RD400) from which the later RZ/RD were descended, were first released in the 1970s as air-cooled two-strokes. Later, (1980), the bikes had a major redesign using ideas Yamaha gained from two-stroke GP and production race experiences. They also became liquid-cooled and had an 'LC' appended to the name to designate this e.g.: RD350LC - some people referred to them as "Elsie". The Elsie is the link between the earlier air-cooled RDs, and the later power valve (YPVS) equipped RZ series. The most common capacities sold in Australia were 250 cc (maximum capacity allowed for new road riders) and 350 cc and were very popular with production racers. The first models of these were supplied without a thermostat in the cooling system and many were retro fitted as they ran too cool even in Australia.

The name changed to RZ in (Australia at least), with the introduction of the variable exhaust valve design in 1983 on the 'K' model. This was a whole new bike and although similar in concept, did not share any parts of the earlier LC series.

The RZ has retained a huge cult following and there are several businesses that are based solely on supply parts and services for it, which is notable given that the bike went out of production many years ago.