The Ferris would have a Kawasaki FS 600V or a Briggs Commercial engine. If the Briggs has the Cyclonic Air Filtration System then I would go with it. I have a 30 HP Commercial Turf engine on my Scag Tiger Cub as a repower and I am very pleased with the air filtering ability of this system. As ZTRs are dusty by their nature of design, a substantial air filtering system is critical to engine life. My Scag has a collection system installed which creates much more dust than normal and air filtration is critical to promoting normal engine life.
The Cyclonic Air Filtration System is identified by the bulging air filter housing that houses the round air filter.