Loud Thumping Noise when Trying to Start

[PanaCon]

Been repairing my tractor (Kubota B21) for some time now, and finally got it to turn over again, drained diesel that was bad from sitting in the tropics for nearly a year, replaced starter, new battery and all connections good.

Despite turning over with the starter the engine does not fire and makes a loud clunking sound from the engine while bellowing smoke, any advice on what I may be able to do to get it to fire?

Is this a safety switch issue? Could it be an engine issue? Just trying to figure this out

Thank you in advance

 

[Dave_eng]

You make no mention of the operation of the glow plugs.
Safety switches do not make noise.

Check that glow plugs are all heating.
Then check as per above from wsm.

Dave

 

[PanaCon]

You make no mention of the operation of the glow plugs.
Safety switches do not make noise.
View attachment 91965
View attachment 91966
Check that glow plugs are all heating.
Then check as per above from wsm.

Dave

I was thinking the engine would not fully fire because of a safety switch not being pressed I'll check these.

Thank you