[ENGINE] 59 beetle engine dies under load.

[s1oww]

Any help would be great.
My wife has a 1959 beetle with the stock engine.
Under load the engine start to die and loose power. It's fine on normal driving, but if you get to a steep hill or use more than half throttle it looses most of its power.
On a long journey I have found putting it un neutral and giving it a rev will help for a bit. It used to sometimes need a rest and that would help it a bit.

I have replaced, plugs, leads, rotor arm, oil change, cleaned and checked air cleaner, new belt and pulley, re done tapet clearances.
I've had the carb looked at by a well Recommened VW guy too.

The car pulled a 100 times better after and we thought it was fixed, but after about 50 miles it came back. It started to play up on the way to our wedding too, but with careful driving it was fine.

Any ideas how I can fix it as she can't drive it far from home incase it dies.

[coopersim]

Fuel starvation maybe?