charging problem

[blackmax]

I’m having a charging problem with my 1989 Merc Black Max 175XL outboard. I think it is the Regulator but its $500 and I want to check before I spend the money. I did the following;
I disconnected the battery cables at the engine.
I hooked a battery directly to the engine and starte3d the engine.
With the engine running I disconnected the battery-the engine continued to run.
I measured the voltage at the output terminal of the engine and I got 0 volts where I expected 12-13

Is the regulator definitely bad??

[boats.net]

First you do not want to disconnect the battery like that. Leave the battery hooked up and check voltage to it. If it is under 12.5-13v then most likely your ret/reg is the problem.

[sillybilley]

Never disconnect the battery while the motor running if the regulator was not faulty it may be now by over loading it. while the motor is running put a multimeter across the battery while the motor is running it should read up to 13 volts or bit more. Do you only have one battery or do have a backup automatic battery change over system.