Yes and Yes, on my square fours.

A few years ago I compression tested my mark 1 square four after running it in following a rebore with new pistons and rings. It has mark 2 pistons with the ‘top hat’, and the head is skimmed (too much by previous owner). My compression tester is a screw in type with a non-return valve so it keeps t...

I’m pretty sure it’s the same as a Bantam one, from a similar year.

The sprocket is almost new - a new one costs £200 with p&p from a UK supplier, here you get the whole wheel including brakes for just a little more.

I thought, maybe wrongly, that the stud was put in at the time of casting - meaning it’s not removable.
Can it be bent straight?
I wouldn’t drill it out, as it would be easier and safer to buy a new brake plate.

Sorry Malcolm, I can’t help you there.

Having a small clear out and this is no longer needed so it’s for sale. Square Four back wheel - comprising rim, spokes, hub, brake drum, brake plate and shoes, with adjusters, springs etc. Basically all of a back wheel for an anstey link square four but without the spindle, bearing or spacers. This...

There should be no play on the gears on their shafts [obviously]. There might be a very small amount of play between the teeth of the gears. If I recall correctly, the coupling gears were paired at the factory for balance and play, and should have matching numbers on them. Is it possible you have a ...

Air leak on the carb flange? Air leak in an inlet valve guide? Stale petrol? Engine not sufficiently warm before pushing choke in?

It may be worth doing a dye test on it to see if there are any cracks.