Starter problems

[steplift20]

I don't like to here about engines not starting, but I had a problem with my 50 hp merc I started thinking what could it be then I said let's start at the most obvious What I would do if I was you is check at the battery's Are the terminals clean and tight, make sure you are good at that end, check the connections on the starter make sure there clean and tight also
Put a multimeter at the battery and see what the volts are then turn the key to start it and see what the volts drop to, you can hit the started with a hammer to free it up Good luck let us know But start at the beginning The most obvious