Nut on starter motor keeps coming off 1987 force outboard

[tinkma]

Hello,
I just took my boat out this weekend. It didn't want to start and when i took the cover off my 1987 85hp force, The starter motor nut came off. (Along with the spring and washer piece that it holds on) i put the spring and washer back on by tightening the nut back down, but it keeps coming loose when ever I restart the motor.
Any suggestions on what i can do are greatly welcome.
thanks

 

[Nordin]

As the nut looks like a regular nut not a (nylon)nut (self locking nut) put some locking fluid at the threads and tight it again.

 

[jerryjerry05]

The nut needs replacing.
It's one that has been peened and a slight bend
has been put on the nut.
You can try hitting it with a punch and hammer.

Unfortunately the nut only comes in a kit and is very
EXPENSIVE!! $40
But it can be found on ebay way cheaper.

DRIVE KIT 90644