No substitute for right tools - that thru the glow plug piston locking tool is great for bending con rods and unbalancing the rotating assembly! The ofna flywheel wrench is all of 6 bucks or so and it will make life much easier - clutch nuts are a breeze with one and no more destroying flywheels with pliers, no more have cluch nut come loose while engine is running and destroying clutch and maybe even end of the crank or buggering threads up so bad can't use them anymore! No more offbalancing engines after they've been pulled apart either. Offbalance engines eat cb brgs and it just gets old really really fast.

I don't own a flywheel puller - mine have always come off easy enough by tapping around on back of flywheel with small rubber mallet. Don't buy an rc one - go to walmart and they're like $3 - auto battery terminal puller.

On your orig quest - I'd spray some wd40 down glowplug and turn it over - then turn rc upside down and put paper towel over glowplug hole and turn it over some more. Depending on what came out - that would make decision to tear down or not - pretty clean - no teardown; bunch of gook - consider teardown. Frankly with that engine, I'd run it til it quits and not worry about it.