i have a 140johnson mod j140tlcrd

i think my prop may be slipping when trying to increase rpm

does anyone know how to check the hub insert on a prop

my prop has the hollow center for exaust, and is a raker 13-1/2 x 20

any help would be appreciated

i know i can get it rehubbed, but i dont want to spend the money on rehubbing this one if i dont need to.