Power loss in B21, mysterious hole

[PanaCon]

Recently I have been experiencing power loss and black smoke from my b21 diesel tractor, I thought it may be injector pump or the tree so I was cleaning that side out and I noticed that under the injector pump was a mysterious hole with a gasket, not sure if that is the cause of the power loss but either way I'd like to know what bolts on there (from my perspective in the photo it is on the left, i.e facing stern) below the injector pump. Photos attached.

Any advice for the power loss or what goes there is greatly appreciated

Thank you!

 

[PoTreeBoy]

I think that's where the fuel shutoff solenoid should go. How do you turn the engine off?

 

[PanaCon]

I think that's where the fuel shutoff solenoid should go. How do you turn the engine off?

There is a length of Paracord that pulls a lever on the same side that must be pulled to disengage the engine (pictured)

 

[North Idaho Wolfman]

If you have black smoke your most likely issue is failing injectors.
Pull them and have them pop tested.

And get a stop solenoid and bolts and install it!

You'll need to know your tractors serial number to get the right one.

Bolts and washers.