I have a late 80's Johnson 50 OB. The motor runs fine, but the propeller does not engage when put into gear. <br /><br />noted: <br />--odd noise (ringing/rattling) from lower elements when given power;<br /><br />--prop turns in reverse when given light power (I did not apply higher power);<br /><br />--visual inspection shows a cracked thrust washer.<br /><br />Any suggestions for diagnosis and/or repair would be appreciated.