Starting problems

I have checked the electrical side and there is spark and the timing is about
correct.
You can see the SU pistons moving up and down when the engine cranks over.
If the engine starts when  Easy Start (ether) is squirted down the carbie then
am I correct that it is either a choke problem or a blockage.
Since the pistons are moving up and down I would assume that there's no vacuum
problem.
The spindles seem to have no wear as the I think that the carbs were recond by
the previous owner (I have had Basil for almost 20 years).
I will take the bowl with the float apart to check for dirt and proceed from
there.

Jim Vass
Down in New Zealand with a '62 TR4.