Generac Power Systems 940-2, 941-2 service manual Recommended Fuels, Recommended Engine Oil

Section 2.1

GENERAL INFORMATION

TIMING:

Valve timing and ignition timing must be precisely controlled if the engine is to operate properly and effi- ciently. Intake and exhaust valves must open and close in a precise timed sequence if the four strokes are to occur. Ignition must occur at exactly the correct piston position, just prior to the start of the power stroke. Timing of valve opening and closing, as well as of spark occurrence, is given in relation to the pis- ton position and the degrees of crankshaft rotation.

Ignition Is timed to occur several degrees before top dead center (TDC) of the piston, to allow time for the air-fuel mixture to ignite and start to bum before the piston reaches top dead center

There must be no leakage past the valves in their closed position or compression will not develop. Likewise, there must be no leakage past the piston

RECOMMENDED FUELS

GASOLINE FUEL SYSTEMS:

For models equipped with a gasoline fuel system, the use of clean, fresh, UNLEADED, regular grade gaso- line is recommended. Unleaded gasoline burns clean- er, extends engine life, and promotes better starting by reducing carbon deposits in the combustion chamber.

Leaded "Regular" grade gasoline may be used if unleaded gasoline is not available.

The use of gasohol is NOT recommended. If it must be used, it should not contain more than 10 percent ethanol. When gasoline containing ethanol is used, special care is required when preparing the unit for storage (see "Storage Instructions"

NOTE: DO NOT USE GASOLINE CONTAINING METHANOL.

NOTE: DO NOT MIX OIL WITH THE GASOLINE.

DANGER! GASOLINE IS EXTREMELY FLAM-

!MABLE AND ITS VAPORS ARE EXPLOSIVE. DO NOT PERMIT SMOKING, OPEN FLAME, SPARKS OR ANY SOURCE OF HEAT !N THE VICINITY WHILE HANDLING GASOLINE. AVOID SPILLAGE OF GASOLINE ON A HOT ENGINE. THERE MUST BE NO LEAKAGE OF GASOLINE INTO THE RV GENERATOR COM- PARTMENT.

GASEOUS FUEL SYSTEMS:

Some RV generator models may be equipped with an LP or natural gas fuel system. The use of such gaseous fuels may result in a slight power loss as compared to gasoline. However, that disadvantage is usually compensated for by the many advantages offered by such fuels. Some of these advantages are:

•A low residue content which results in minimum carbon formation in the engine.

•Reduced sludge buildup in the engine oil.

•Reduced burning of valves as compared to gaso- line. No "washdown" of the engine cylinder wall dur- ing cranking and startup.

•Excellent anti-knock qualities.

•A nearly homogenous mixture in the engine cylinder.

•Fuel can be stared for long periods without break- down.

DANGER! GASEOUS FUELS ARE HIGHLY

!VOLATILE AND THEIR VAPORS ARE EXPLO- SIVE. LP GAS IS HEAVIER THAN AIR AND WILL SETTLE IN LOW AREAS. NATURAL GAS IS LIGHTER THAN AIR AND WILL ACCU- MULATE IN HIGH AREAS. EVEN THE SLIGHT- EST SPARK CAN IGNITE THESE FUELS AND CAUSE AN EXPLOSION. THE USE OF LEAK DETECTORS IS RECOMMENDED WHEN GASEOUS FUELS ARE USED. ALL CODES, STANDARDS AND REGULATIONS PERTAIN- ING TO THE INSTALLATION AND USE OF GASEOUS FUELS MUST BE COMPLIED WITH.

RECOMMENDED ENGINE OIL

Use a clean, high quality, detergent oil that is classi- fied "For Service SC, SD, SE, SF or SG". Use no special additives with the oil.

•During summer months (above 32° F. or 0° C.), use SAE 30 oil. SAE 10W-30 oil is an acceptable sub- stitute.

•During winter months (below 32° F. or 0° C.), use SAE 5W-20 or 5W-30 oil.

•DO NOT USE SAE 10W-40 OIL.

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