Weber help

[Buzz word]

Since I put my kit car together it has always seemed a bit rich so I decided to have a go at it today armed with a Gunson colour tune and some new jets. It's a standard pinto engine on twin 40's.

what it was ....
130 main
f16 emulsion
180 air correct
45f9 idle
40 pump

This was recommended by the dave andrews calculator thing which seems to be held in great esteem.

I changed the jets to...
190 air corrector
40f9 idle
35 pump

Which apart from the emulsion tubes brings it inline with the jets speced in an example in the weber speed pro book.

The car seems to run better and the screws are within 2 turns of totally closed and give a nice blue flame. The car has lost its stink of unburnt fuel and doesn't pop and bang on over run.

What is does now is between about 2.5-3.5k on the drive (not tested on the road) it pops from the carb. This is supposed to be a lean characteristic but if I put the colour tune in look at whats happening the pops coincide with yellow flashes so show rich. After 4k the popping stops. This is if i hold it steady in this range. Freely revving sees it run fine.

I think this is about the range for the jets to crossover from idle to main so does anyone know how to smooth it out? I tried bumping the mains to 135 and it made no odds. it used to have the odd pop in this range but its a lot worse now I have the newer jets in. How can I improve that range or smooth the crossover?

I haven't road tested it yet as the throttle cable needs replacing so I don't know if its an issue that will dissapear under load or not. I don't really want to put bigger jets back in as I don't think its right the car smells of unburnt fuel.

Any ideas? I would take it to a rolling road but most people dont deal with carbs anymore and the one locally that does and has worked on another guys car does not leave me impressed. His car eats sparkplugs even more than mine and smells alot worse whilst driving the ecconomy is also even worse than mine.

[Buzz word]

Main Choke is 34mm. aux venturi's are 4.5.

I don't think that a colour tune and mix screws will do anything more than adjust the idle mix but what I expected to happen was by leaning the jets off would affect the mix at idle. The colour tune would therefore help me to get the engine back to a reasonable level of tune or atleast let it tick over propperly.

The jets aren't being changed at random I have a few different opinions from well regarded source I am trying. I will freely admit I am not the authority on webers. I am just describing what happens now and asking for suggestions in regard to what may aleviate some popping in the mid range. I have a few jets at home so could try out some of the ideas. I was hoping for replies like the daddy who offers advise based on the symptom. I am trying to learn a bit more about how they work but what with mine being the original holbay sort and carbs really going out with emissions rulings information is scant.