About: http://webisa.webdatacommons.org/76544922

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	Engine speed would be one possibility, anvil shape and gap another, air paddles, scooped out/worn area behind the cutting blades, some sort of chute blockage, air not getting into the disk area, etc etc...
http://www.w3.org/ns/prov#wasQuotedFrom	arboristsite.com