WEN 56405 Power Pro 4050 Watt - Manual (Page 14)

Step 1 - Fill Oil
The generator is shipped without oil. User must add the proper amount of oil before operating the
generator for the first time. The oil capacity of the engine crankcase is 20 fluid oz.
Select good quality detergent oil bearing the American Petroleum Institute (API) service
classifications SJ, SL, or SM. (Synthetic oils may be used.) Use the SAE viscosity grade
of oil from the following chart that matches the starting temperature anticipated before
the next oil changes.
Figure 1- Engine oil recommendations
To fill oil to the crankcase, follow these steps:
1. Make sure the generator is on a level surface. Tilting the generator to assist in filling will
cause oil to flow into engine areas and will cause damage. Keep generator level!
2. Remove the oil filler/dipstick cap from the engine as shown in figure 2.
3. Using a funnel, add the appropriate type and amount of oil into the crankcase. The
crankcase is full when the oil level has reached the second thread from the lip of the
opening (see figure 3).
4. Check for oil leaks. Reinstall oil filler cap before starting engine.
Figure 2- Unscrewing the oil cap Figure 3- filling oil
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