A7SS choke/carb issues

[BUNNERS]

Afternoon All
I have an issue with my 1961 A7SS. End of last seasons but the old bike away in workshop, it had run very well all season. took it out of hibernation today and it will only run on full choke. choke off and it stops immediately. My son took it for a quick spin of about 5 miles to get it nice and warm with choke on and ok. turn choke off and it stops. any ideas would be most welcome.
Bunners

[limeyrob]

Clean top hat filter, Blow (gently) up fuel lines to clear tank gauze (if they are still there). If its a monobloc remove and clean the idle jet, remove the hex nut and clean the main jet.
If its a concentric then odds on its the idle circuit which is a pig to get clean.  The bio-ethanol seems to create white power that blocks concentric idle circuits solid.
Try getting a can of carb cleaner with the tube on and blow though the idle circuit.

[BUNNERS]

Good Morning Limeyrob
Thanks for your reply
Late yesterday afternoon I replaced all of the jets with brand new

376/239 1" carb
Main jet   270
Pilot jet  30
needle jet 106

I got these details from the Amal Reference catalogue
But alas the problem still exists
Bunners

[V500]

You need to clean the passages as well as the jets though.
Air line, High-E string, whatever it takes.

[BUNNERS]

Morning V500

My intention this morning is to put the carb, suitably striped down, into my Ultra sonic cleaner and see if that makes any difference.

Bunners

[V500]

Worth a go, but no substitute for blowing and rodding, in my experience.

[limeyrob]

The bio-ethanol petrol dries to a rock hard white clag that even carb cleaner struggles with.  At least its a Monobloc which you can rod, the Mk1 Concentrics are near impossible.

[BUNNERS]

Ultra sonic cleaner did the trick now running as sweet as a nut

[limeyrob]

I now run my carbs dry after every run.  I'm not sure it will stop the idle circuit blocking but its worth a try.  I don't remember these problems before ethanol in petrol.