The tool has to be exactly at centre height as well as the correct angle. Nev

The concentric is a much better carburetter than a monobloc... Nev

Sticky bottom feed floats can cause that. BTH are a good magneto. Magnetos usually show up when pulling at low rpm. Nev

A decent 2 litre Ford Escort would kill it. or if you want serious performance get a Ford Focus RS. Handling and braking on par with the performance. The original tires would handicap the Morriss. I suppose we all yearned for a "wolf in sheep's clothing" for a drag at the light's. Instant ...

Oversize the thread and make a suitable replacement adjuster. 26 TPI British Cycle thread. Doing it that way will give the strongest result . Being on the chain side you don't want it to fail. Nev

They are not that radical anyhow. Nev

The original 30-on has has a rather flimsy item there. I'd try to adapt the later one.Nev

John, clean out ALL the idle system holes carefully and check the float height and it think she will run sweetly. Looks like your jet block is a good fit. Brass (and Diamonds)are forever.. Nev

It's definitely a Lucas pick up from the Late 20's period. Usually at least one of the projecting prongs that locate the CORK gasket in place are broken off Around that period the Magneto's are only held on by 2 hard to reach bolts on Ariel (Same as if a TT BTH is fitted to later "competition' ...

Having another look at what you have It appears as if the CAMSHAFT teeth may be a more modern profile and not matching the other. It's NOT meshing deep enough, also.. I don't think ARIEL ever changed after going to the finer teeth in the early 30's but many gear cutters don't carry the earlier tooli...