Dellorto question - starting to run rich Options

[bandjoey]

2.0L w/Dellorto 34's. Been running this setup for about 10k miles since they were installed, and car runs good.
These were suggested by CB when I installed the carbs.

140 main
2 emulsion
60 idle
Valves and timing about 2k miles ago

Recently burning more gas, a rich smell, and a sooty tail pipe and no tail pipe smoke.
Car tuns as always. Nothing new in drive ability.

The CB book suggests going one size smaller on the mains for a sooty tail pipe. . However, this is a recent issue.

Other Things to check over? Do jets wear out an need replacement?
Thanks!

[r_towle]

1)Check your fuel pressure.
2) after sitting for the winter you may have junk inside. That could, and does, get lodged in the seat valve that it attached to the float. That can hold open the float providing too much fuel to the carbs, run rich
3) timing, dwell, point, plugs, cables (10k is too long imho)

I use an electric fuel pump and I have a fuel shut off valve so I can turn off the fuel while the car is running and let it die. No fuel in the carbs for winter. It's stock in a 356, but they have mechanical fuel pumps.

[ljubodraz]

Noob here but I've got Dell 40s and had a similar problem until I rebuilt them. I did a lot of reading here beforehand though. What r_towle says is a great start. The other possibility with Dells is the "Dell Drip" when lead plugs within passages of the carbs back out and short circuit the passages allowing fuel to drip through the progression ports.

If nothing else fixes your problems, check for the drip. One way is to remove the tops from the carbs and fill the float bowls and see if they drain without the engine running. I'm not sure how much you can attribute to evaporation though. Another way is to look down the carbs throats to look for wetness near the progression ports but I think this can be hard to properly discern.

If it's a stuck needle valve, you'll be able to see the fuel dripping from the accelerator ports (right term?) down the middle of the carb's throats from above, dead-center. This would be easier to check I believe.

The best way I can explain the drip is by thinking of a garden hose filled with water in the shape of an upright letter "U." As you know water seeks its own level so the water at the tops of the U will be at the same level. Engine vacuum will suck fuel through the carbs U passages when running only. If the lead plugs are leaking they introduce a leak near the bottom of the U and your carbs bowls will drain. Fixing the plugs is best left to pros in my opinion.

To answer the other question you had; no, jets shouldn't wear out. Jets only get plugged up. Only seals and gasket wear and require periodic replacement.