larger body to fill the need for bigger throttle bores in all-out performance ... two had to be a smoother and easier throttle operation this resulted in the design ... major feature of the hsr42 is the flat throttle slide assembly with roller bearings ... unlike butterfly throttle valves which obstruct the carburetor s ... venturi at all throttle openings creating airflow turbulence ... precise air/fuel metering the flat throttle slide allows an unobstructed venturi at ... full throttle thus flowing more air and carbureting ... more precisely at all throttle settings the roller bearings on ... throttle slide provide a light throttle action which offers smoother control ... and allows the use of a very light throttle-return spring with its 42 mm venturi the hsr42 ... for stock and mild tuned evolution sportsters flow bench tests by jerry branch show ...
stock style 1990 to present big-twin throttle and idle cables 720448 total kit 731452 ... breather kit and hardware uses stock throttle and idle cables 720542 total kit for ... cam easy kit uses stock manifolds choke cable air cleaner and throttle cable easy kit ... for 1200 sportster models 1994 to present includes hsr42 ... with same year stock style bigtwin throttle cables these must be ordered separately ... 720447 easy kit for 1200 sportster easy kit for evolution big-twin models ... and chrome cover uses stock style cables note does not work with cruise control ... and instructions use with stock style throttle cables and air cleaner cover will not ... cleaner uses 1990 thru 1995 stock style cables 234852 economy kit 731453 economy kit t ... carburetor only mikuni style push pull cables not for use with zpn 720455 720446 ...
