Problem re starting my OMC 150 Hp outboard engine

I have a 1993 out board OMC 150 Hp. I just bought it and have been told that it has been serviced.
It started fine and after one hour cruising when I turned it off, it wouldn't start. Keep cranking but the engine does not come on.
Did I may be pump it too much and flooded it or could be something else?
I need some advice

Peter
You need to give a lot more information to get some help on here. Tell us your starting procedure step by step. First thing I would check would be your battery. These old motors had to be turning over 300 rpms to generate a spark. You can crank it forever below that speed and it will turn and turn but never spark. Make sure your battery is strong and all connections are shiny and tight.
Also be careful cranking too long at a time. Doesn't take much to burn up your starter.
Flooding is possible, but not likely as that condition would correct itself after a short wait.

The other obvious possibility is that the neutral switch is out of position in your control box.

The neutral switch is for cranking only!