1978 Evinrude Outboards 9.9/15HP Service Manual, Page 23Get this manual
cRemove orifice plugSee Figure 3-14For orifice plug identification, see Specifications, Section 2 _-ORIFiCE PLUG
cCheck the needle valve seat with magnifying glass; if seat is nicked, scratched, or worn out-ofround, it will not give satisfactory service See Figure 3-16 The valve seat and needle are matched set; if either is worn, both parts must be replacedUse new gasket when installing the needle seat
Figure 3-14Carburetor Orifice Plug Figure 3-16Inlet Needle Valve Seat Wear
CLEANING, INSPECTION, AND REPAIR
GENERAL INSTRUCTIONS Clean all parts, except float, in solvent and blow dryDO NOT dry parts with cloth as lint may cause trouble in the reassembled carburetorBe sure all particles of gaskets are removed from gasket surfacesFlush all passages in the carburetor body with solvent and remove any gummy deposits with OMC Accessory Engine CleanerCertain solvents will not remove this gum which accumulates particularly in the float chamber and on needle valvesFLOAT AND NEEDLE VALVE aInspect float and arm for wear or damage If the cork float has become oil-soaked, discard it and install new oneCheck float arm wear in the hinge pin and needle valve contact areasReplace if necessarybInspect the inlet needle valve for grooves, nicks, or scratchesIf any are found, replace float valve assemblySee Figure 3-15Gum or varnish on the needle valve must be removed with OMC Accessory Engine CleanerDO NOT attempt to alter the shape of the needle valveGOOD