Key bound
is a term
used to describe the action
that takes place when installing the prop on the shaft and the key slides
forward in the keyway on the shaft and rides up on the end of the keyway
most forward (like a sled runner) and in turn prevents the prop from
seating on the shaft taper properly which in turn holds the prop off
center, this in it self will cause a horrendous vibration as the weight of
the prop even though only a few pounds ,acts like an eccentric or off
center counter weight ,can bend or break the shaft ,egg shape the bore of
the prop as well as create other problems that will just destroy the day
you've been waiting for all winter long ,then to have to call that
boat hauler or a diver to remove and reinstall the prop in a proper manner
and hope you didn't cause any other damage. To be certain this don't
take place , slide the prop onto the shaft taper without the key, make
sure prop is snug on shaft and touching the shaft all the way around the
taper by snugging up the prop with the nut ,then with a marker (felt tip
type) make a mark on the shaft where the hub stops as a reference point
for when you replace the prop for use. Replace the key with a new one
,this is something you should have on board as a spare at all times ,and
the key should be replaced each time the prop is reconditioned ,I normally
keep my old key as a spare on the boat. ie. if the key fits tight it should
be ok.