[MT-2500]

I answered your private message but I would also get a manual oil prssure gauge hooked up on it and see if you have any oil pressure.
The old squirt out lifter is not a very good check.
What engine and have you heard any rod or main bearing thumping in it?
If the motor is sludged up bad or if you have put any cleaner additive in it your oil pump screen may be clogged up.
And possiable twisted or stripped oil pump shaft.
What kind of oil filter does it have on it?
MT-2500