Are you sure the temperature gauge is reading correctly? Sounds like your dash is failing. Try reading the thermostat housing temperature and compare it to the water pump inlet to see how much heat loss the radiator is giving. Infrared heat guns are fairly cheap now and can be within 10 degrees of the actual temperature.
Place the lens about an inch away from the surface for an accurate reading. Use it on painted dull surface, rubber and shiny parts will give a bad reading.
The most common issue I find for overheating is missing baffles. If the seals in the hood or around the radiator are missing, they must be replaced. Too much air flow will be sent from the engine into the radiator and it will overheat. Next verify the cores are absolutely clean. Never wash the radiator with a water hose. You need a pressure wash and compressed air to dry it out. If air is used regularly, wash should not be needed. Clean grass lands or house demolition cause the most trouble with plugged radiators.
Overloading is a common problem for these machines too. Often I find the operator try to replace a 320 size machine with this small one and it just cannot do the same work. Oversized buckets and extra attachments just add to the problem. If engine power is not correct, this too can cause overheating. Lugging the engine is often too much for the cooling system to recover. Engine speed must be keep at high idle and fan cannot slip. Fan belts must be maintained and pulleys replaced when worn. If machine came with the high ambient cooling package, the correct parts must be installed or it will not cool correctly. Water pump, pulley, fan belt and sometimes the fan itself can be different.
Did you find the screen and clean it?
Did it help your power problem?
Did you test the pressures?
Did you replace the main relief?