Dellorto blues, I've reached my limit Options

[barefoot]

For several years after After I but it all back together the car's been running fine, had to clean one carb once and that worked fine. Now it's getting worse won't idle, it just dies after I let off the throttle. Runs strong at higher loads but very poor at idle & low load. I've cleaned the carbs enough that think I could do it blindfolded. I know the points dwell is OK and I haven't touched the advance. Using a heat gun i can measure header pipe temps just before muffler and one cylinder on each bank is way lower temperature than it's neighbor after holding the rpm's just above idle speed.
Think I'll pull the carbs off and do a compression check just to rule out one thing.
Can't even do a synchronize without a smooth idle.
Is there someone in our group who is Dell 40 expert so i can send carbs off to ???
I've prided myself as a competent mechanic but this has got me on the edge.
Not having fun anymore (IMG:style_emoticons/default/headbang.gif)

Barefoot

[Osnabruck914]

Another common culprit could be air leakage where the intake manifolds meet the block. Are those bolts tight? Are those gaskets in good shape? An air leak there and you'll never get things to adjust properly.

Osnabruck914

[porschetub]

Another common culprit could be air leakage where the intake manifolds meet the block. Are those bolts tight? Are those gaskets in good shape? An air leak there and you'll never get things to adjust properly.

Osnabruck914

(IMG:style_emoticons/default/agree.gif) that would explain why it will idle with a bit more tip end throttle,seen this before ,cheers.