hey fellas!
can anyone help me with this ?
for some time now my car has been backfiring through the carbies when cold....runs great when warmed up.
it's a 1640 t1 engine with dual kadron setup and cheapie extractor exhaust, 009 dist.and compufire module, otherwise standard...carbies seem balanced with throttle plates? equal and mixture screws turned in till stumble then back 1/4 - 1/2 turn.
any ideas?

Have you tried to do a search?

There are heaps of threads about "popping" through carbies.

Read hear

http://www.lowbugget.com/main_page.html 

basically -

Popping out the top of carb:
Incorrect Jetting.
Clogged idle jet.
The distributor is not advancing correctly
incorrect accelerator fuel squirt adjustment.
Small main jet.
To big of venturies.
Check your linkage, make it open the carbs not close or hold them open.
Is the timing correct? I do not recommend setting your timing at idle or static.
This is just for getting it to start and should be set afterwards with a timing gun set at full
advance.

My guess is to lean as it goes away when warm

Could be the linkage. When the engine "grows" when it gets hot the linkage comes good which might explain what it does only when it's cold, especially with Kads. my 2c

I had a bug do that and i found that i had a few inlet tappets that needed adjusting:o

thanks all.
did a search....nothing new there.
i will double check for air leaks, then
i guess i will richen mixture a little and see what happens...then maybe advance? the timing a little.
met a mechanic at work a couple of weeks ago who believes the quality of fuel is responsible...says FI systems can cope with variable fuel better than carb...says quality of fuel has been poor for a couple of years?

I'd guess your choke (if you have one) isn't working properly. In colder temperatures the cooler air would be more dense and so you'll be effectively running lean but as the engine warms up so would the air going into the engine.

your linkage is out, you just need to adjust.

yeah..thanks Craig..i thought i had linkages right but on reflection i have been tricked by them before

:blush