1971 Johnson 40HP outboards Service Manual, Page 20Get this manual
bInspect the inlet needle valve for grooves, nicks, or scratchesIf any are found, replace float valve assemblySee Figure 3-11Gum or varnish on the needle valve must be removed with OMC Accessory Engine CleanerDO NOT attempt to alter the shape of the needle valvecCheck the needle valve seat with magnifying glass; if seat is nicked, scratched, or worn out-ofround, it will not give satisfactory serviceSee Figure 3-12The valve seat and needle are matched set; if either is wornboth parts must be replacedUse new gasket when installing the needle seat WORN