Prop speed tests for an O.S. .91
Engine guru Clarence Lee tached this engine w/various props
Prop Size RPM
13x6 12,500
13x8 10,400 using a 13x8 prop,
13x10 9,500 Hobby Services tached
this
14x6 10,900 engine at 11,300 rpm
14x8 9,500
6-24-99
14x10 8,400
15x6 10,200
15x8 8,100
16x6 8,300