Reviving NOS Webers, Initial Settings? |
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Reviving NOS Webers, Initial Settings? |
bbrock |
Mar 20 2019, 08:55 PM
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#1
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914 Guru Group: Members Posts: 5,269 Joined: 17-February 17 From: Montana Member No.: 20,845 Region Association: Rocky Mountains |
I didn't want to hijack the other thread but have a question about my own Webers. They are Italian 40IDFs I bought in the late 80s or early 90s. Other than finger tight bolting them on to my engine to see how cool they looked, they have never been used. No fuel has touched them. I don't remember if I even opened them to set the float levels. BUT... they were stored in a humid basement for several years before I moved to a civilized climate. So, the magnesium housing is tarnished on the outside and the plating has deteriorated on a few of the levers and such. Pretty minor stuff from what I can see.
My question: is there is anything special I should do or check other than inspecting for corroded parts and normal setup as I prep these for service? |
72hardtop |
Nov 2 2020, 06:19 AM
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#2
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Member Group: Members Posts: 120 Joined: 11-September 13 From: Seattle/HB Ca./Fujieda-Japan Member No.: 16,378 Region Association: Pacific Northwest |
My procedure....
Start and warm up the engine. Make sure the two drop links for the throttle linkage are exactly the same length, and disconnected. You can use a 8mm thin ignition wrench to snap them off. Turn the mixture screws all the way in (lightly seated) and then 4-5 half turns out. Turn the air bypass screws all the way in. Snug the jamb nuts on the air bypass screws. Turn the idle speed screws out and then in until they just touch the levers (then add 1/2 turn in) Should run like a tractor. Put on your hearing protection and start the car. Allow it to warm to normal operating temp prior to tuning. Use your SNAIL and find the barrel that pulls the most. We'll call this one baseline. Balance the barrel in the other carb that pulls the most with the idle speed screw. (if you have a Uni-syn, give it to someone you don't like and purchase a SNAIL airflow meter) Go back to the other carb, with the baseline barrel. You will have one all the way in, then use the air bypass screws and balance the two barrels to each other. Go to the other carb and do the same thing. Keep the idle speed low 850rpm or so. All four barrels should pull the same (within 1 point of each other) amount of air at this point, if not repeat air adjustment procedure. Snap the throttle linkage drop links back on the carbs. If the idle changes then you need to barely adjust the linkage mounts so snapping the drop links on, doesn't change the side to side idle balance. Start back at the baseline barrel and adjust the mixture screw in or out, to get the smoothest running and highest idle. (No further adjustment in) Do the same with the three other mixture screws. If you have to turn the mixture screws out more than two turns (from lightly seated), you've got the wrong jets. Recheck side to side and individual air balance, adjust as needed. Keep the idle speed low 850rpm or so. Road test the car. If you get snapping and popping out the intake, it's generally a lean condition. If you get heavy exhaust fumes, or popping out the exhaust it's probably too rich. If you get a flat spot or popping out the intake at between 2800 and 3200 rpm, you probably need larger idle jets. If you change/alter the timing, jet/s and or A/F mix screws you redo LBI on all screws. All tuning is done on an engine that is at normal operating temp. If the jetting is correct it should run like crap when cold idle/progression circuit). |
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