any tips for tuning weber 34ict? Options

[JOE M]

Curious about how to set the carbs up.The timing is close but may be out slightly.I started by turning the air mixture screws all the way in and than backing both off by 2 1/2 turns to start. I let the car idle and than I move 1 side until the car runs rough than back off the other way about 1/2 turn.I did the same for the other side. It runs ok but pops through the exhaust every now and than.It gets better when I take the throtle linkage off.I think my biggest problem is seting the idle speed screw. Is there something I should do prior to starting any other alignment?I read the procedure but I am stumped. What typically causes it to pop through the exhaust?I did check the vacum on both sides and they are real close ( within 1 of each other).

[McMark]

The exhaust can seem tight and still have a leak. Getting the pipes to seal to the heads can be a PITA!

A little trick I learned from fiid & mightyohm is to hook up your ShopVac so it's blowing, then carefully tape the hose (or use a friend) blowing into the exhaust (blowing backwards towards the heads). Then you can crawl under the car and hear/feel where it might be leaking.

Sometimes people think they can feel for leaks with the motor running, but the air from the cooling system is always blowing there, so you can't feel anything.

And things may have 'changed' since you set the timing/valves because now the motor is running better and perhaps you have hotter exhaust, or some other condition that was bad for performance, but was preventing the backfire. Problems masking problems.

You have to take the long systematic approach and deal with each problem as it becomes apparent. Everything done right is a step forward, even if it feels like a step backwards.