Good idea with the oil or the Aerostart to find out the quickest way. Also it assumes that the fuel is free flowing all the way to the pump. no blockages inside the tank, tap (if fitted), or outlet of the filter bowl.
I had a McDonald Super Imperial Crude Oil Engine I rebuilt. It was never going to start off the crank and this is with new rings and gaskets etc plus overhauled hyvid bronz fuel injector. In the end I belted it to the PTO pulley on the tractor. That bought it to life and once running for quite some time. After killing every mosquito for a mile radius it now starts off the crank

It's out of my fild of expertise but admire your attempts at making improvements. Do you think the torque would have changed or HP rating?

Go right back to basics. Is there rubbish inside the fuel tank, is the fuel tap clear and allow the fuel to flow free. Replace the fuel filter and check for free flowing fuel all the way to the pump. Make sure then that fuel pumps freely to the injectors rack and that fuel is making it to the injector. Finally make msure that all injectors are atomising the fuel.

After that check spill timing. Change air filter so that it can b reath as you need air to mix with atomised fuel to ignite. What is the compression like? This should keep you busy for a while. Don't rush over any stage of this as it only takes one thing to stop it. But it does sound like a fuel supply issue as it starts and runs for a short time but will restart and do the same.

Good thinking Hugh. Our Club used a lot of dry ice to help shrink the cyliner liner in the Clubs big Tangye engine. Even then it was stubbourn but got it out in the end.

What way are you intending to freeze the shaft and warm the bearing? On a small shaft I was able to put it in a plastic bag and hid it in the freezer inside overnight. Never got caught either. Then when it was time I was able to get enough heat from a heat gun for stripping paint. You don't need a huge variance but enough to do the job.

Okies. Did not know EdDee b ut I did know Glort ad we almost caught up one time as he travels past our front door when he travels up the coast. Un fortunately it never happened and I have a feeling I know why.

Sorry dax021, not heard of the place

Yes, I have been guilty of using the cold chisel on the final drives of the David Brown tractor but they were quite large in diameter as well. It came with all the warnings of how you MUST tighten them with a C spanner so they are very tight. Ignored and tightened them as tight as possible using the same tool they were undone with, a cold chisel but a blunt one.