OMC Stern Drives And Motors 1964-1986 Repair Manual., Page 156Get this manual
The fuel system includes the tank, fuel pump, fuel filters, carburetor, connecting lines, and the associated with these itemsRegular maintenance of this system, as aid satisfactory performa from the engine, limited changing the fuel and cleaning the arrest at regular intervalsIf sudden increase in consumption is noticed, if the engine does not perf properly, and if the has been checked and found be clean, then overhaul, including boil-out, of the carburetor, replacement of the fuel pump may be in orderIf the choke should stick in the closed position, the engine will flood making very difficult to startT this condition, move the idle warm up lever the wide-open position as the engine crankedThis action will the unloader linkage open the valve and help the flooded engine When the engine hot, the system starting problemsA engine down, the insidethe fuel bowl may rise and the fuel actually boilAll vented allow this pressure to the atmosphereHowever, of the may percolate over the high-speed nozz and overflow into the manifoldIn this raw fuel to vaporize enough burn, considerable must be added lean the mixtureTherefore, the only remedy open the as wide as possible and the engine until enough is drawn in provide the proper mixture for the engine to startNEVER move the lever back-andforth in hot engineThis action will only compound the problem by adding more already too-rich mixtureIf the needle valve and seat assembly is leaking, excessive of the intake manifold in the following manner: the engine shut down, the pressure in the fuel line will fuel past the leaking needle valveThis fuel will raise the level in the fuel bowl and fuel overflow into the intake manifoldA continuous overflow of fuel the manifold may be sticking which would an high level of fuel in the bowl and overflow the manifold