HELP! before i go crazy Options

[D0ctorg00se]

Ok, so i have a '74 2.0 that was carb converted (unkown single dual progressive) when i bought it 5 years ago. Since then i have done the 009 dist, facet fuel pump, etc. (but of course no new cam, yet). Exhaust is monza quad tip, in good shape no holes. The fuel lines have all been replaced. The car has really been a dream considering i live in Blacksburg, VA and drive it daily. I upgraded to dual delorto's which ran fairly well considering they were used but one actually cracked and began to leak fuel into the crankcase. So i just recently put a pair of brand new dual EMPI, HMPX 44's on and i just can't get em right! Now they are synched and linkage should be fine I have recently adjusted the valves and they should be fine (i keep saying "should" be b/c im no expert and if it could be the problem then it could be). The car starts right up, idles fine (not perfect but good enough) and at full throttle it is fine. It is at part throttle that the trouble arises. Basically unless i push it hard past half throttle it runs like crap. Maybe at like an eighth or less it is ok, like easing off really slow. But as soon as i get on the throttle part way it lags, pops, sputters, hisses, jumps, and just has a fit unless i get on it more or feather it goofily. So i've basically tried the mixture anyway it can be (while still being able to start) rich lean whatever and while sometimes it seems better than others its still not where i feel like it should be with a brand new set of carbs. So someone please help me out no mechanics have ever worked on a 914 down here so i hate taking the car in to have some hilljack screw with it. I havent checked/adjusted the timing or dwell yet but im not sure if i need to. Someone please hook me up with some knowledge. I know you gurus have the uber knowledge i need. Let me know what you think.

[SLITS]

Go to the library and read about venturi theory.....velocity thru the venturi is critical in a carburetor for atomization of fuel. If the "holes" are to big, the airflow at part throttle does not provide sufficient "signal" at the fuel ports to pull the fuel and atomize it properly. You get big dropplets and lots of air, causing stumbling and poor driveability in low and midrange.

While Webers have interchangeable / replaceable venturis, I know nothing about the carbs you are running. You could call and ask if the venturis are replaceable. If so, you could downsize them a bit to get the effect you want. Decreasing the venturi size will cause a bit of loss on the upper end of the RPM range, but you engine is not designed to spin up in the high ranges anyway.

Short intake manifolds can lend to this problem also. As the intake valve closes, there is a reversion wave that comes back up the intake tract, disturbing the flow thru the venturi. Longer intake manifolds can lessen this problem.

This is very general. While in the library, study carburetor theory for a fuller understanding. It's all there for you to learn.