#91 SPORTSTER CHOPPER INSTALL#
The new assembly was "caged" and a whole lot easier to install than 1957-1976 engines, which had 13 loose roller bearings.
#91 SPORTSTER CHOPPER UPDATE#
Redesigned engines cases for 1977 featured a new gerotor oil pump, which was not interchangeable with 1957-1976 models.Īnother update was the pinion shaft bearing assembly. Read More: Sportster Cafe Racer Engine Upgrades Later in the year, Sportster models switched from Bendix to Keihin carburetors. To help celebrate America's 200th Birthday, Harley-Davidson offered special Bicentennial Edition models, with commemorative decals applied to the gas and oil tanks. Approximately 5,300 Sportsters were produced in 1975. New cases were eventually fitted in 1977. Other bikes that switched from right to left shift were the Triumph Bonneville and Norton Commando.ĪMF's remedy was to continue using the existing engine cases and route the gear-shift linkage across the back of the engine, thus avoiding the expense of re-tooling. In 1975, new federal regulations required all motorcycles sold in America to have left-side shift and right-side brake controls. With the influx of quicker and cheaper Japanese bikes, Harley-Davidson's share of the 750cc and larger motorcycle market had fallen to 21 percent. This led to a 101-day strike by union workers. To increase profits, the corporation began streamlining production and cutting the workforce. Under the control of AMF, build-quality seemed secondary. Production total for all model Sportsters was 19,960 units. Harley-Davidson was now just one of dozens of divisions in a corporation, and quality control was becoming an issue. These two holes held the supports for the original solo seat.ġ973 was the first year that turn-signals became mandatory on all motorcycles sold in America.ĪMF-produced Harleys began rolling off the York Pennsylvania assembly line, although the AMF logo had been appearing on gas tanks since 1971. Read: 1974-1977 Sportster Caliper RebuildĪlso this year, the frame was modified, with the steel casting eliminated and replaced with steel straps which covered the two upright frame tubes having the open holes. The fiberglass seat and tail section, known as the 'boat-tail' was available for the second and last year. The distributor was moved from the right-side engine case to inside the gear-case, now employing an automatic advance mechanism to aid starting. On the other end were the customizers, who embraced the clean, integrated symmetry of the compact V-twin engine.Ī unique year for Sportsters 1971 was the last year of the 900cc and first year of the new engine cases. On one end were the racers, who loved its tourquey power and the endless ways to squeeze out more. And in that time, the Ironhead's fan-base had widened deeply. His recorded speed of 265.492 mph would stand for fifteen years.īy 1971, Harley-Davidson was selling an average of 6,500 Sportsters annually, which was triple the amount from a decade ago. Owned by Manning/Riley/Riveria, the pilot was famed Harley-Davidson factory rider Cal Rayborn. The engine ran on 70 percent nitro-methane. Inside was a small cockpit and a modified XLR motor, bored and stroked to 1,480cc (89-cubic inches). The streamliner body was a 15-foot-long aluminum tube, with a cross-section of only 23 inches. It was here that a Sportster-powered streamliner motorcycle broke the world speed record in 1970. The Bonneville Salt Flats in northwestern Utah have long been a mecca for high-speed competition.
Sportster-Powered Bonneville Record-Holder
#91 SPORTSTER CHOPPER TV#
The TV show and the bike were both popular, prompting Harley-Davidson to offer a "Bronson Red" paint option for several years.
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