Finally corrected the serious backfire issue i had exhaust leak was found (crack at header mount flange area) and repaired...long story but excessive/loud backfire on decel has been FINALLY eliminated. Overnight however i developed a sputtering/popping thru carbs. Uneven and rough acceleration up thru 3k RPM and higher. idle is irregular but constant - either a little high or a little low but steady...varies on the day. I have noticed since the carbs were rebuilt last september fuel mixture out of the exhaust at startup...i assume too rich? new plugs already dark. i've only put on a couple hundered miles since carb rebuild so not much experiance since rebuild.

what could happen to cause the engine/carbs to take such a drastic turn from one day to the next with touching them? Could this be valve issue?

for those not familar with past issues my set up is 74 2.0 with weber dual IDF 40's.

on another note, anyone in balt/dc going to hershey?

Have you checked the wires, cap and rotor? Also is the timing off?

Check the idle jets, easy to remove just be carefull not to loose the O ring, it

can stick to the carb or to the jet, it's better to have something under them

or you will play Hell finding them on the engine or ground.

When you remove them holed them up to the light to check for dirt , blow them

out and replace. I am know expert be I think it runs on the isle circuit up to

3,000. They are very small and plug easly. It would be a good time to replace

the fuel filter. There right at the base on the outside ,( towards the fender )

easy to find. Finger tight

Mine did the same ,worked perfectly after , good luck ! Let us know, results.

Dave

I'll try the above and post results. Thanks gents

You may be jetted a bit rich and fouling plugs.
Does the idle get better if you drive it hard and get it hot, and then get shitty again when you start puttering around town or get stuck in stop and go traffic?

Zach

I'd check the idle jets first as already mentioned. Check pump jets for even spray. A stuck pump jet check valve will cause lean pops and poor acceleration. A linkage out of adjustment will also cause similar issues.

I wish that were the case Zach...much worse than that now. i would say that was how she was ran until the other day - before the current sypmtoms. i'm going to dig in today - raining like shit here so stuck inside anyway.

I know that i can get to the idle jet but to access others does it require that the carbs be torn down?

thanks. is there an easy way to tell if linkage out of adjustment?

I can't get my car a right either. 3.2 87 Carrera engine with 46 PMO's. Same symptoms as yours. It's been to 3, count them, 3 shops in the past two years.
I have an old aquatint, up in Summit Point I'm thinking of giving a call.

Use the search function on this site and you'll get boat loads of weber tech and tip info. Below is one I found that should help you out.

http://www.carburetorclinic.com/weber_tech.htm

Thank you but I don't tinker anymore.

I'm going to look for a shop that I can have it transported to and get it sorted out.

great link...thanks jim