The generator shuts off after 30 minutes with an oil level alert but oil level if full

Check if there any alarm on monitor by pressing button several times. It has code like E-number. Replace spark plug, fuel filter. Clean carburator, spark arrester. Check wiring of thermosensor.

sounds more like a fuel problem not oil being spilled on it but check the oil level some have a low oil shut off see if you can keep it running spraying carb cleaner in the air filter that will tell you if it is a fuel problem more so a fuel problem if you left fuel in it for more than 30 days

You have a carburetor problem. Stuck float or clogged filter. Gas cannot get into the carb as fast as it is used. Letting it sit for a few minutes will allow the bowl to fill.

What elevation are you at? Start with simple things such as clean the air filter, fresh gas, clean/replace spark plug. Also check oil level most generators have a low oil shut off yours may be attempting to shut down

The oil recommended by the manufacturer is 5W-30. You will need 7.0 U.S. quarts or 6.6 Liters

If the fuel filter (strainer) is OK, carb gives enough fuel for the load you apply, air filter is dry and clean, your problem may be the low oil level protection.
Check if generator is at level position.
After the oil is distributed in all the engine its level may go less than the measuring sensor level. Try to put some more (not much) oil. 
If this will not help your measuring sensor may be bad and switch off when the oil gets hot.

do a full service on it , new spark plug /air filter foam , full oil change , also chane the oil in the pump end , carefully remove the carb bowl and remove any dirt/rust/water etc

ive seen gx160 engines last 10 years no problem and those were hire machines

hope this helps if it does please vote

2 things to check , carb bowl for rust/water/debris, if the engine has a oil alert fitted try disabling this ( after double checking oil level ) as these can sometimes become itermittant

Over-full can be just as bad as under-full. The crank will make contact with the oil and cause a froth of oil and air. Air is a very poor lubricant and will cause serious engine damage. Park the vehicle on a perfectly level surface and shut the engine off. Wait at least 30 minutes and then check the oil level. If it is over-full drain out enough to get it down to the full mark. Never ever over-fill an engine. Your car holds 4.5 quarts with filter change.

Sounds like oil pressure switch. Is oil level good? Switch could be bad

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