My 1954 KH has a monobloc carb and the air filter. It would amaze me if my air filter rubber was a decent seal onto the carb. Turn on the petrol, shut the air slide and give the carb a very brief tickle and she will fire up and run reliably, usually first kick. I think your only problem has been hol...

Hello Bert, Knowing where you are, and what you mean by OEL would help us to help you. For instance, if by OEL you mean oil, then the oil pressure gauge as fitted to your bike is something I can usually repair, but it isn't normally worthwhile to send it from (say) India to here in the UK for that p...

My analysis for the 1933 model year suggests that zero Square Fours went to the USA that year, although 22 went to Canada, representing 5% of Square Four production that year.

Like Roger, I do not anticipate more research during the summer months.

What year is the VG?

If you have a spare slide with a greater cutaway, try that. Modern fuels seem to be requiring changes from standard carburation and richness of mixture at small throttle openings appears to be one of the problems, to me at least.

The late Mr R Saunders told me that he had scrapped the prf converted frame which came with Peter Ferbrache's 250.

I have a NOS adjuster available if you want one.

In my experience, these threads eventually suffer from rust and seize up. Freeing off from this may well be the cause of your problem. So make sure that the thread is suitably protected with copper grease or similar when you re-assemble.

I have sent you a private message.
Paul

I had a 1957 NH where the previous owner had filled the GB box with grease, just the same as he had done on his earlier Ariels. It worked perfectly well.

With an oil filter in the return line I have gone over 20,000 miles without checking the sludge traps. I know of people who have done much more than that but I don't know their frequency of oil changes, how clean the engine was inside when it was rebuilt, etc.