Mercury Mariner Outboard 225 3 Litre Service Manual 1994, Page 338Get this manual
STEERING ARM EXTENSION BRACKET INSTALLATION
STEERING COUPLER ASSEMBLY AND INSTALLATION Position outboards so that they are facing straight forward(Distance between threaded hole centers of steering arm extensions MUST BE equal to distance between propeller shaft center lines)Lubricate inside of rubber sleeves with 24-C Marine Lubricant and slide sleeves on steering couplerWork rubber bushings onto threaded ends of steering :yesThread jam nut on starboard steering eyeThread steering eyes equally into coupler, so that distance between hole centers of steering eye ball joints is equal to distance between threaded hole centers of steering arm extensionsExposed threads of steering eyes MUST BE of equal length and threads MUST NOT extend out from coupler more than 2-34 in(70mm)
Secure steering arm extension bracket to each outboard's steering arm