Another Go on the Yanmar SB12

[RW Sailor]

Hello again, so the game with the Yanmar continues:

My 12hp Diesel made some trouble before but I got it all fixed so far but this is where I am stuck now:
Starter was changed because the old one died, the ignition switch was changed because the old one didn't ignite any more, after that I had it working this morning but i keeps dying after a few minutes. So I though there might be air in the system, bleed the whole thing and try again: Runs just fine for about 5 Minutes before it dies again (slowly - well, 3 seconds from idle in neutral to nothing) and now when I turn the key there is one single klick and nothing more.
I thought the starter might be stuck and gave it a few taps with the hammer but didn't help.
Any other suggestions? Would also be greatful for anybody who wants to have a look in person (if in Annapolis..) or any other kind of advice!
Thank you so much already!

[RW Sailor]

Another thing I just checked and that does not make sense to me:
I can turn the shaft by hand, but I can't turn the engine - even if the decompression is pulled... Any ideas!?

[TheOffice]

Did you check the battery voltage and alternator output?

[TheOffice]

if its in neutral you should be able to turn the shaft - the cone is disengaged.

[RW Sailor]

I can turn the shaft, that works, just the engine itself I can't...
THe batteries are charged, shouldn't be an issue as well... And alternator output is there - or was there when the engine was running, not right now though...

[TheOffice]

Guessing there are 2 problems. Starter jammed and fuel system issue. Did you replace a filter recently? Possible it did not seal correctly? Otherwise, check all connections and hoses from the tank to the pump.

[RW Sailor]

I did change one of the filters today, but bleeded the lines afterwards and double checked all is closed nice and tight. Jammed starter sounds right, but... how do I solve that problem? The casual knock on the side didn't do the trick...

[TheOffice]

Check the connections and voltage at the starter to be sure it is not a corrosion/wire issue, then loosen the bolts and re seat the starter.

[RW Sailor]

Originally Posted by TheOffice

Check the connections and voltage at the starter to be sure it is not a corrosion/wire issue, then loosen the bolts and re seat the starter.

Tried that and even removed the starter just to be sure the engine is blocked and not the starter...
So even with the starter off I can't move the engine at all - turn the center piece anyways...
any ideas about that? The engine didn't run for more than half an hour in 5 minute pieces so it doesn't make sense to me. Oil level is fine, so was the temperature...
Any other options on the cause?!