Here is a link to the Yamaha web site. You can get owners manual (download  
or view) and also look at parts manual for your particular model and year.
 
_http://www.yamaha-motor.com/outboard/service/viewmanuals/viewmanuals.aspx?ls=
outboard_ 
(http://www.yamaha-motor.com/outboard/service/viewmanuals/viewmanuals.aspx?ls=outboard) 
 
I'm not sure what you mean by swivel lock? I know there is a bolt which you  
can tighten on most motors to adjust the tension for turning, but I'm not  
sure if this is what you are describing.
 
Rummy