NC30 start fine today.
Took it out for a ride.
Then it started to run a bit rough after 20 min or so.
I carried on marking my way home. It was a bit hit or miss on how it was running.
Then it stopped and would not start.
After a bit of pushing I gave it a go and started but was rough.
Anyway off I went then it stopped again. Bit more pushing.
Then tried start and started. This time I made it home.
But now it will not start.
Any ideas?

Flat battery, lights bright, check battery voltage?

Embarrassingly I had this

I had left the fuel tap on reserve! So it ran until it ran out of juice. I left it for a few minutes (allowing the tiny remainder of fuel to fill the carbs again). Then It started and ran for a bit then finally conked out (Obviously).

Please let me know if this is what happened to you as I don't want to feel like the only idiot in Kent!

Battery is new and was turning the engine over.
I have fuel in the tank. Wish it was no fuel as I pushed it past 2 fuel stations.

vacuum hose either loose, or collapsing in the heat. so, check that... :)

My mistake, engine cranks but does not fire, fuel tap vacuum issue perhaps or tank vent blocked.

Right. Update
Fuel tap checked and working
Fuel dumped and replaced with 5 litres of fresh
Carbs off stripped and cleaned
Think I’m save to say I have.
When I was turning it over it was firing on 1 cylinder.
Any more ideas out there? Please

Just had it running on 2 cylinders
Front right and rear left

Is your vacuum hose in good condition?

Be wary of flooding, or otherwise fouling the plugs. You'll be needing to take them out to dry.

Tap will flow with a hose that is "ok" but unless you can be sure there are no splits, then you'll not get enough fuel.

When you took carbs off- was there fuel in each of them?

Vac hose in good condition.
Plugs are getting wet.