Hi John,
they are made after 1930, (A7, slutch plug).
If you mesure the stroke and type of biggend, I can thell more.

There is much wear to the club exhaust valve stems if placed in iron guids, they have strange lines and are battered after only 5000km even in a side valve. Who has the same experiëns? If an exhaust valve is placed in the inlet, the same wear is seen. As an experiment I have welded a new valve disc ...

Just heath up with mild hobby torch, have the oil can ready, if a oil drop avaporates, stop heating.

It would help if your bending tool is hot aswel.

Maybe the hole in the petrolcap is blocked.

There is no spacer or nut between the frame and stay check your frame against the seat.
At the rear of the frame, no spacers between frame and mudguard, that would mesure the frame.
Adrie.

Hi Jim,
maybe your 1950 Ariel never had a trouble light.
Adrie.

Hi Alan,
the twin inner case is offset at the crankcase side, where the singles are in line.
The outside deck is the same as single.
Adrie.

Hi John,
try a heath blocker between the head and carb.

Adrie.

Hi,
take the tank bottem out, sandblast the stuff away, repair the leaks, weld the bottem in again, forget the sealant.
Kind regards Adrie.