covers. Upon removal of the compression release mechanism in 1974 due to updated starter, the square cover at the left exhaust valve was continued. Brake modification notes: Drum fronts on early models cannot be changed. Pre '77 & post '77 fronts have different (offset) brake discs, the wheels swap but not the discs. Drum rear wheel into rear disc frame needs the rear drum frame swingarm too. Disk rear wheel into rear drum frame needs the rear disc frame swingarm and also needs brake master-cylinder lugs welded to the frame. Handling differences on swapping rear wheels:- Standard rear tire is 110/90-18. Special rear tire is 130/90-16. Because the Standard tire is narrower it will tend to steer a bit more quickly. Because the Special tire is wider it will tend to be a bit steadier in a straight line. Overall gearing is not changed from the Standard, as the two tires are essentially the same outside diameter. Prior to the XS-B model, the bike had a reputation for speed wobbles but adjustments to the 1975 setup overcame these. 1976 models had the front brake caliper moved to the right fork leg, behind the fork as opposed to in front of the fork. This placed the brake caliper nearer the steering pivot center-line, requiring slightly less effort to steer. Mid-'77 the front forks had a major redesign: fork tube diameter increased from 34 to and internals were changed (although this also holds true for various years of the same tube size). The entire fork assembly (with triple tree) will swap either way but fork parts are not equivalent. Also the brake caliper changed from a dual piston cast iron design for the fork to a aluminum single piston floating caliper for the forks. The brake caliper mounting lugs on the fork sliders are of different spacing for the and forks so the calipers can't be swapped. End of production The XS 650 was produced until 1985. The last model year was 1983 in the United States, with Canada, Europe and other markets continuing into 1984 and 1985. However, many US models remained unsold for some years due to overproduction and an economic recession and brand new 1982 and 1983 models could still be purchased in 1987 at some dealerships. Design Engine Like the contemporaries in its class the XS 650 has a 360° crank angle. This provides an even firing interval