I just completed a Weber conversion on my '75 2056. I need a Weber expert! Here are two of my latest specific questions;
1 When setting "best lean idle", when I screw the idle mixture screw in, waiting for worse running, one barrel doesn't get worse and lets me turn the screw all the way in (shut). Should I be really scared! Keep in mind that I just got the car, and had not solved a trailing throttle miss problem, before I removed the d-jet. Related?

2 If I install 6 inch velocity stacks, do I have to re-jet? ( I know, it's childish, but I always wanted to try this, O. K.? )

Are you sure you are screwing in the mixture screw and not the air balance? If you are sure it's the mixture screw then something is wrong with that carb.

6" velocity stacks may look "cool" but they won't help the performance of your engine.

Thanks, Perry. Incidently, the air bypass screw had to be backed out about four turns to balance the air on the carbs (on the same offending barrel). I'm always hesitant to dis assemble a carb, but I think You are right. I don't know what I'm looking for but I'll inspect everything. The large gaskets are new, but I thought there might be an air leak. Also, I may have over-tightened a throttle shaft nut.
I'll prolly use the 6" stacks for some modern art! Dave

Check the basics basics. Do you have spark to that cylinder? Clean out the idle jet. Clean the spark plug. Then see what's up.

Like Zach said, start with the basics; but I'd suggest verifying your valves are good before tuning your carbs.
Mike

I agree. I made the assumption that the engine was fresh and valves recently set. Clearly, not a good assumption to make. If they have not been checked, check them.

That said, when getting carbs set it is common for at least one spark plug to foul and need cleaning. Especially if the engine is new and timing is not quite perfect yet. Lots of low idle speed, low engine heat, poor timing, unsynched carbs, etc will coke up a plug pretty quick.

Zach

Dave,

Do a search on "carb tuning" and you can add my member name 9146986 in the search by member name function, and you'll find my carb tuning proceedure. I can re-post it if you need me to, but it seems like I'm re-posting it about twice a month.

PK

Thanks Guys, I'll try all this stuff.