starting issues on my 1951ES2 500 cc

...using the right technique?

Briefly:

Petrol on, air slide closed, light flooding (different bikes need different amounts).

Ignition set to 1/3 - 1/2 retarded (again bikes vary as to what they like).

Throttle very slightly (1/16" or so) open - very important.

Lift the valve lifter and give the kickstart a couple of gentle pushes through (NOT kicks).

Release the valve lifter, let the kickstart return to the top then push the kickstart down till it reaches compression.

Lift the valve lifter and push the kickstart down 3 or 4 inches.

Allow the kickstart to return to the top; release the valve lifter and give a long smooth swinging kick keeping the throttle almost closed.

Your bike should have a magento so doesn't use the battery at all for starting or running.

Check and clean out your pilot jet, replace old fuel with fresh fuel and try again. Put your old fuel in your car, the petrol injectors will not be bothered by off fuel that a carb will be bothered by.

That's what he means. I have the same bike, if I 'over-flood' the carb and the plug gets wet then

no amount of kicking will get it going unless I dry the plug off and kick it over a few times (with plug out) to dry the combustion chamber out. 276 carbs seem sensitive like that, monobloc not so much. In a nutshell, 276 carbs are a bit juicy/leaky so err on the cautious with the petrol until it's going.

With the pre mono Amals I find they need flooding ,but respond best if you wait till any overflood has stopped dripping  (i catch drips on a rag that I remove before starting ) ,then kick with a small throttle opening. Once running I hold the revs up  to clear any excess.  If you have a steep downdraught carb  then  a light tickle only . Sometimes it pays to turn off the fuel tap at this point. And turn back on after starting . Most starting issues seem to improve with a mm raise in the fuel level , when a remote float with its easy adjustment is a boon.

??