Owner`s manual
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Keep the oil level as near as possible to full, but do not overfi ll. Overfi lling may cause
foaming and engine shutdown. Replace the cap tightly to prevent leakage. And if
your generator has an oil fi lter, change it when you change the oil.
Do NOT check the oil level while the generator is running, because hot oil can be
thrown out of the dipstick hole, causing severe burns.
Gasoline Engine Oil Quality – Use oil meeting any of the following API
performance categories: SJ, SL or SM where SM is currently the highest quality
available. Look for the “Energy Conserving” designation to optimize fuel economy.
Diesel Engine Oil Quality – Use oil meeting any of the following API
performance categories: CF, CF-4, CG-4, CH-4, CI-4 or CJ-4 where CJ-4 is
currently the highest quality available. The use of synthetic oil is not recommended.
The use of oil meeting API performance category CF-4, CG-4, CH-4 or CI-4 while
burning fuel with a sulfuric content greater than 0.5% or CJ-4 while burning fuel
with a sulfuric content greater than 0.0015% is not recommended as oil service is
negatively impacted.
Oil Viscosities – Use the following chart to select correct viscosity grades for
expected ambient temperature range.
32°
10°
0° 100°
100°
100°
-20°
-20°F
SAE-30
Viscosity Grades
15W-40
10W-30
10W-40
0 20 40 60 80 100°F
50°
5W-30
NOTE: Multi-grade oils (such as SAE 15W-40) are recommended for year-round use in Cummins Onan
liquid-cooled engines, or as a good all-season oil for air-cooled engines.
NOTE: SAE-30 is the preferred summer grade for optimum oil consumption control in Cummins Onan
air-cooled engines.
Coolant Recommendations
Quality of the coolant in your liquid cooled generator is an important factor in
performance and service life. Always use a 50/50 mixture of ethylene glycol based
antifreeze and water which should be mixed thoroughly before adding to the
generator’s cooling system.
Water: Use clean, soft water from a tap, distilled water or pure rain in your mixtures.
If hard water or other forms of natural water are used, your generator’s cooling
system is more liable to oxidize, corrode and create deposits faster.
Antifreeze: The core components of ethylene glycol based antifreeze are acidic.
Introduction of the cooling water creates alkaline properties that can rapidly
corrode light metals. Be sure to select high quality antifreeze with corrosion
inhibitors to prevent cooling system problems. Also – be sure to maintain the
cooling system as use of antifreeze coolant for an extended period of time can
result in increased corrosion.
Prevent Fuel Varnishing
If You Don’t Run A Tank Of Gasoline Each Month, You Could
Be Risking The Performance Of Your RV Generator.
If you store your RV over the winter, or don’t operate it often enough to refuel
the gas tank every month, you could develop a fuel varnishing problem in your
generator engine.
Fuel varnishing is a gummy residue that clogs the generator carburetor and fuel
pump. It’s caused by the deterioration of fuel that sits in the engine too long. And,
it happens in a surprisingly short period of time. Depending on fuel quality and
storage conditions, gasoline can deteriorate in as little as 30 days. As long as you
refuel frequently with fresh gasoline, and exercise the unit regularly, fuel varnishing
is less likely to occur. But if you leave the same gasoline in the tank for several
months, you’re very likely to have problems.
Fuel varnishing affects many engines but it’s more noticeable in generators because
the engines are smaller. Even the slightest decrease in effi ciency has a big impact
on performance. A generator with varnish buildup may start but run like it needs
a tune-up. It surges, accelerating and decelerating, but rarely settles at a stable
operating speed. In many of the gasoline powered units, engine speed directly
affects generator voltage output and frequency. As speed increases/decreases, so
does the voltage and frequency.
The only ways to prevent fuel varnishing are to treat the contents of the tank
supplying fuel to the generator with a fuel preservative and to exercise the set.
Cummins Power Generation has developed a fuel preservative and stabilizer,
OnaFresh,
™
specifi cally formulated for Cummins Onan generators. We recommend
adding this preservative to the fuel, especially on infrequently used RVs.
Emptying the tank won’t prevent fuel varnishing because a small amount of fuel
always remains in the generator carburetor. If you plan to leave the tank empty, we
recommend that you add a special mixture of fuel and a preservative before you run
the tank dry so the residual fuel contains the preservative.
Once varnishing has occurred, adding a preservative won’t correct the problem.
You need to add a fuel cleaner, and manually scrub the varnish from the fuel system
parts. Cummins Power Generation offers Premium Fuel System Cleaner for use
with Cummins Onan generators
By understanding how to properly care for your RV generator and protect against
fuel varnishing, you’ll enjoy better performance and longer, service-free operation.
It may seem strange that “not” using a product causes it to fail faster. With
generators, though, that’s exactly the case.
Premium Fuel System Cleaner and OnaFresh, along with other Green Label Parts
™
maintenance products can be found at your local Cummins Onan Authorized RV
Service and Parts Dealer. To locate your nearest dealer, visit Funroads.com.
Important: Problems caused by fuel varnishing will not be covered under
warranty
.