1991 Mercruiser 4.3 …Have power but will not crank.

[BMK10]

1991 celebrity 4.3 mercruiser Alpha 1

I have power at the battery but the ignition switch is doing nothing. Gauges turn on.

I tried to bypass it by jumping the solenoid terminals but the engine still would not crank. The solenoid was sparking when I tried to jump it however so I know there’s power.
Is it the starter itself is bad or possibly the NSS?
Not sure how to test further from this point.

Thanks for any help.

 

[alldodge]

If you jumped from the small terminal on the inside closest to the block and the starter post then either the starter has an issue or the motor is locked up

Find your slave relay on top the motor. Jump across the top larger terminals and see if it will crank