Let me be clear: wet concrete is one of the most hostile environments on earth for mechanical equipment. It is highly abrasive, chemically corrosive, and the dust it creates when it dries will choke an engine to death in hours. If you want a vibratory screed to last more than one season, preventative maintenance must become a religion.
At the end of every single pour, while the mud is still green, the machine must be thoroughly washed. I make it a rule on my sites: you never let concrete harden on the blade or the lower eccentric housing. Once it cures, you have to chip it off with a hammer, which damages the magnesium blade and throws off the balance of the machine. Many veterans will spray the blade and the lower housing with a light coat of form oil or a specialized concrete release agent before the pour begins, which makes the cleanup process a hundred times easier.
Mechanically, the focus is on the engine's air intake and the vibration dampeners. The heavy vibration will back out untreated bolts; applying thread-locker to the engine mount bolts is a mandatory first-day modification. The air filter must be checked daily. If cement dust bypasses the filter, it acts like liquid sandpaper inside the engine cylinder, scoring the walls and destroying compression. A clean machine is a reliable machine.
