I suspect the stock old ignition struggles to cope and spark breaks down easily if its even a little out of tune with raised comp.
I have the same problem, expecting elec ign to have it running a lot better.

I think hes running an a15 carby i gave him a couple of years ago if it has the auto choke still.

i think its the exhaust that may be holding the breathing back. as the carby ran fine on my a15.

An engine makes power by burning fuel. The more fuel that it can burn [in the correct fuel/air ratio] then the more power it can produce. Geting the fuel in there is the job of cam, exhaust, ports, induction etc. etc.

Raising the compression will increase the efficiency of the burn, but this is offset by the fact that we are limited by the octane rating of the available fuel.
As the compression pressure increases, so too does the likelyhood of detonation, which must be countered by reducing the amount of spark advance.

Retarding the spark, as we know, reduces the maximum amount of power that an engine can produce, so there seems to be a balance, beyond which an increase in compression becomes counterproductive on pump fuel & this seems to be somewhere around the 9.5 - 10.5 to 1 from my observation.

Are you now running this engine on expensive premium fuel?

It could be a million things but chances are it's just that the engine can't breath.Aren't you running the A12 carby and original 1000 exhaust? so to begin with it was never going to go as well as a standard A14 because it was choked by the carby and exhaust.

You should piff the wideband up it's clacker and see how bad the mixtures are perhaps?

After driving sr20det and ca18det you may be just a little dissapointed in the performance. Or mabey it just won't come to life. What is the compression like? What carb are you running? Was it off the 1K or tha A14? How many Km's were on the engine before you started? Did you replace the timing chain also? Was the cam dialed in? How many KV is the coil producing at idle through to desired rpm? What leads are you running? What are the points like? Condensor?

Don't assume just because a part is new that it is working o.k. I have replaced many parts over the years, expecially electrical, that were no good from the box.

Too many variables for a motor like this. Sometimes things just go bad. I remember that it was pretty weak on the dyno day, even by A14 standards. There has to be an underlying problem with it and throwing performance parts at it won't fix it. Unless you accidentally replace the failed part.

WHAT CAM IS IT ?

Drill out the main prim jet to 1.3mm, 1.6sec, remove choke, remove sec flap plate, check vacuum advance works, limit it if possible because it will be advancing to about 40

needs more fuel + air and timing

i already had a stock a14 in my 1000 wagon but the other day did the head gasket so decided with the help of sikyne and toddat to shave 80thou off the head to up the comp and add a mild cam. it goes a little better but not much. what gives? timing is at 14 deg at idle tappets set etc. am i missing th a series love? i'm hunting for an elec dizzy but that surely won't transform it! it has stock a14 ex mani and carb tho...