Please check your engine ground cable to the battery - for testing make a very high quality cable and attach it to the starter mounting bolt - this is to guarantee that the starter is gettting its full supply of amperes from the battery, You should also ensure that your battery is actually good - a badly prepared tap water/well water battery will not reliably start the engine.
sounds like a really bad overhaul if the mechanic is giving you a reason that the engine is too tight. To test his theory - tell him to remove the glow plugs from the head when the engine is hot and remove the shutoff solenoid wire from the pump, attempt to crank the engine.
If its really tight to spin - then the bore/hone job is bad and the piston clearance is too tight - in actual effect your engine is seizing. I call this a really really bad overhaul. Trying to make the engine wear out to let itself free is the worst kind of practice you can know of.
if it spins free then you have a badly timed injection pump - to place the pump on dead on accurate timing you need a dial guage to measure plunger stroke, your timing is getting really super advanced which is causing the engine to fight itself. A good 2C diesel starts on the first hint of starter revolution.
The nozzles also play a role in timing, if the break pressure is not even on all cylinders the engine will act like its out of time, e.g. if one cylinder injection nozzle opens eariler e.g. 1300 psi compared to 1700 psi - the cylinder will run advanced than the rest.
