so i'm cleaning out my idle jets today to see if it will help my carb popping, and what do find but 3 jets sized "60" and one sized "50"...

would this be the source of my carbs misbehaving? i also have been looking at previous posts and an idle jet size of 60 seems a bit large, no? i am guessing my weber carbs are "40s", but how do i check? there must be a part number on the carb bodies somewhere, but i couldn't really figure out where... thanks!

Four or six? I would guess four...

You can't even really tell by the imprinted number. In the old days racers or peope without a lot of jets handy would tune by reaming the holes bigger until they were too big, then soldering the holes closed and then drilling them back out in the last good size. Unless you know those carbs you really need to measure the orifices or use new jets.

Bitch to tune like that, isn't it?

The place to check the size of the carbs is by where the carb bolts onto the manifold on the opposite side of where the fuel inlet is. You should have 52 or 55 idles as a starting point if you are running a 1.8 or 2.0L