the compression ratio in the earliest b engines was reduced to 8.7:1 from the 9.0:1 of the triumph engine, but power reportedly increased. the redesign kept the unusual waterpump arrangement, which consisted of a cast aperture in the block, and the pump shaft with bearing, seals and impeller pressed into the aperture, but improved the design of the seal. the pump is driven by a jackshaft and helical gear. later b engines used a fine tooth gear which is easily damaged and is a weak link in an otherwise very reliable engine. the early b engine was one of two (the other being the honda cvcc) that were able to meet the stringent emission requirements set by the state of california for 1975 without resorting to a catalytic converter.