webers running lean

[hantonyc]

hi folks ! im having an issue im running a bit lean at steady cruising speed or light acceleration , im running f15 emulsion tubes (what came std in the webers) ive read in the weber tuning manual that most tubes weaken the mixtures exactly where i am having my issues , but that the f7 tubes will richen in these area , but they also put the f7 tubes in alcool running vehicules

my question is , anyone tried f7 tubes ? if yes, do they work ?? thanks

[ncbrock]

cruising below 3k rpms or above? If your below 3k and lean you need to look at your idle circuit, probably need to step up to a larger idle jet. If its above 3k you need to look at your main circuit. Emulation tubes should be the last part of tuning.

[hantonyc]

under 3000 rpm,i run a souped up 1.8 16v , im already using 55f9 idle jets , to have a resonable idle im like 1.5turn unscrew ( otherwize im a pig rich at idle ) so i cant really go up in jet size, thats why im thinking to use the tubes.. any thought ?

[candm]

under 3000 rpm,i run a souped up 1.8 16v , im already using 55f9 idle jets , to have a resonable idle im like 1.5turn unscrew ( otherwize im a pig rich at idle ) so i cant really go up in jet size, thats why im thinking to use the tubes.. any thought ?

like mentioned above, save changing emulsion tubes for last if needed. you should have F16 tubes, not F15. also, for your idle, you should be about 1/2-3/4 turn out. how many turns out are your mixture screws?

[hantonyc]

my mistake i run f16 tubes , my mixtures screws i run about 1.5 turns out ( that why im saying i cant go up in jets size otherwize i ill alway be too rich at idle even right now i am a bit too rich), idle speed screw im about half a turn out.

[ncbrock]

Are they synced properly with a syncronizer? If they arent it will cause lean symptoms when trying to step on the throttle

[hantonyc]

yes they are perfectly i check them almost on a daily basic. someone told me i will always have that problem since i have a small motor with big cams and compression what do you think ?

[candm]

my mistake i run f16 tubes , my mixtures screws i run about 1.5 turns out ( that why im saying i cant go up in jets size otherwize i ill alway be too rich at idle even right now i am a bit too rich), idle speed screw im about half a turn out.

if they are the newer spanish webers , your mixture screws should be turned out from 2-3 turns. if they are slightly over or under that is ok but are you sure that at 11/2 turns out is where it runs best? if it is, you need a leaner idle jet. start them all at 21/2 turns out from seated. starting with #1, turn in the mixture screw 1/4 turn. wait about 8-10 seconds. if the rpms are still the same, turn the screw in again 1/4 turn. when you notice the engine start to run rough, turn that screw back out 1/4 turn. now do #2 the same way then the rest. at this point, you will have approximately your lean best idle. i usually go about another 1/8th to 1/4 turn, depending on how its running. you will have to re-sync your carbs after and your idle. get that part right then repost how its running

[hantonyc]

if they are the newer spanish webers , your mixture screws should be turned out from 2-3 turns. if they are slightly over or under that is ok but are you sure that at 11/2 turns out is where it runs best? if it is, you need a leaner idle jet. start them all at 21/2 turns out from seated. starting with #1, turn in the mixture screw 1/4 turn. wait about 8-10 seconds. if the rpms are still the same, turn the screw in again 1/4 turn. when you notice the engine start to run rough, turn that screw back out 1/4 turn. now do #2 the same way then the rest. at this point, you will have approximately your lean best idle. i usually go about another 1/8th to 1/4 turn, depending on how its running. you will have to re-sync your carbs after and your idle. get that part right then repost how its running

yes they are the new made in spain 4 progession holes 45's , i have a wideband so i know where my mixture is right the problem is that if i put a 50f9 idle jets, it runs like crap execept for the idle and half-throttle and full throttle , and with the factory installed 45f9 its barely drivable so ive put 55f9 wich now is the way it runs the best in "normal" driving condition and with the transition from idle to main circuit but it made me a bit too rich at idle and ive started from scratch today and im 2 full turn on my mixture screws .. so that should be "ok" but that dosent make my cruising or light acceleration problem gone , btw i re-synchd them again today after playing with my mixture screws.

no now im a bit stuck, cant go up in jet size, already got the richest air bleed, the only thing left are the tubes but im not really familiar with them ..

[candm]

yes they are the new made in spain 4 progession holes 45's , i have a wideband so i know where my mixture is right the problem is that if i put a 50f9 idle jets, it runs like crap execept for the idle and half-throttle and full throttle , and with the factory installed 45f9 its barely drivable so ive put 55f9 wich now is the way it runs the best in "normal" driving condition and with the transition from idle to main circuit but it made me a bit too rich at idle and ive started from scratch today and im 2 full turn on my mixture screws .. so that should be "ok" but that dosent make my cruising or light acceleration problem gone , btw i re-synchd them again today after playing with my mixture screws.

no now im a bit stuck, cant go up in jet size, already got the richest air bleed, the only thing left are the tubes but im not really familiar with them ..

the 45s i have only have 3 progression holes, so, a bit leaner than what your progression should be from off-idle. if you dont have an air leak causing problems, then go to a 55 idle jet with the next richer air bleed ( i dont remember what is next ), but stay with the 55 portion of the idle jet. also, if you did check your mixture screws as i mentioned above, where is your lean best idle? 11/2 turns out? 2 turns out ? basically. once you find that and you are within the 2-3 turns out on the mixture screws, stay with that fuel portion of the idle jet ( the number ), and start working on the air bleed .

[candm]

also, there are richer air bleeds available

[hantonyc]

my best idle is with my 50 size jets, but it dosent drive good at part throttle, wich is the reason ive insttalled 55 size idle jets wich now makes the car drivable except for the cruising and low rpm speed, but i know its not the right jet size since im out of spec on my mixtures screws , will buy 50f6 and see, if still not enought i will try my f7 tubes

[81type53]

What's your A/F @ Idle? What Is It at WOT? When you say lean, what are your numbers? How Is It through progression??

[hantonyc]

idle i am between 13.5 and 14:1 , wot i and between 11.5 and 12:1 , progression if i push the gaz i become a bit too rich but it works, if i try to maintain a cruising speed it goes 17-18:1 and hesitate same thing if i give light throttle .. if tried the foam filters its running way better but at WOT i am at 10:1 so it dosent work but for now i run it that way , i am making an alu plate in my hood so when its closed it will stop the flow of air .. also ive ordered new pump jets (55) and new idle (55f6) also will try f2 tubes if it dosent work.