The carburetion or fuel injection,and the ignition principles of engine operation must be understood in order to troubleshoot and repair an outboard moto’s fuel system or to perform a proper tune-up carbureted motors.-From the article content Johnson evinrude 1992-2001 outboard repair manual
if you have any doubts concerning your understanding of engine operation,it would be best to studey the basic operatiing principles of an engine as detailed under troubleshooting in section 1,before tackling any work on the fuel system.
The fuel systems used on engines covered by this manual include multiple carburetors and electronic fuel injection,For the most part,the carbureted motors covered here utilize fuel-enrichment for quicker cold starting in the form of an electric primer solenoid (though a fewmodels are equipped with a manual primer),similarly,although a few motors may be rigged to require pre-,oxomg pf tje fuel and oil,the majority of evinrude/johnson v-motors utilize the general engine system specifications chart in section 2 for more details as to what systems where commonly used on what motors,but keep in mind that during boat/motor rigging,systems such as VRO2 or an electric fuel primer solenoid could have been added(or even deleted),for details on the vro2 oiling system,please refer to the section on lubrication and cooling.
fuel system service cautions
There is no way around it ,working with gasoline can provide for many different safety hazards and requires that extra caution be used dring allsteps of service,to protect yourself and others,you must take all necessary precautions against igniting the fuel or vapors(which will cause a fire at best or an explosion at worst)
For starters,disconnect the negative battery cable EVERY time a fuel system hose or fitting is going to be disconnected,it takes only one moment of forgetfulness for someone to crank the motor,possibly causing a dangerous spray of fuel from the opening,this is especially true on the high-pressure fuel circuit of ficht fuel injection(FFI)motors,where just truning the key to on will energize the fuel pump.
Gasoline contains harmful additives and is quickly absorbed by exposed skin,as an additional precaution,always wear gloves and some form of eye protection(regular glasses help,but only safety glasses offer any significant protection for your eyes).
because of the dangerous conditions that result from working with gasoline and fuel vapors always take extra care and be sure to follow these guidelines for safety:
- keep a coast guard approved fire extinguisher handy when working,
- allow the engine to cool completely before opening a fuel fitting ,dont’t all gasoline to drip on a hot engine.
- the first thing you must do after removing the engine cover is to check for the presence of gasoline fuemes,if strong fumes are present,look for leaking or damage hoses,fittings or other fuel system components and repair.
- do not repair the motor or any fuel system component near any sources of ignition,including sparks ,open flames,or anyone smoking.
- clean up spilled gasoline right away using clean rags,keep all fuel soaked rags in a metal container until they can be properly disposed of or cleaned,never leave solvent,gasoline or oil soaked rags in the hull.
- Don’t use electric powered tolls in the hull or near the boat dring fuel system service or after service,until the system is pressurized and checked for leaks.
- fuel leaking from a loose,damaged or incorrectly installed hose or fitting may cause a fire or an explosion,always pressurize the fuel system and run the motor while inspecting for leaks after servicing any component of the fuel system.