weber IDF idle circuits, which way to blow Options

[machina]

runs rough at idle and part throttle, if i remove the idle jets and the mixture screws, do i want to blow it out down from the jet openings or up from the mixture openings?

i seem to remember that its better to do it one way in particular so you don't jam debris into the passages.

also, any advice for synching the carbs?

[SirAndy]

runs rough at idle and part throttle, if i remove the idle jets and the mixture screws, do i want to blow it out down from the jet openings or up from the mixture openings?

i seem to remember that its better to do it one way in particular so you don't jam debris into the passages.

also, any advice for synching the carbs?

for the jet's, you wanna blow them out opposite to the gas flow. meaning, you blow into the little hole so the obstacle hopefully comes out the big hole ...

as for the passages, make sure the bowls are empty of gas, otherwise you'll have a nice mist of gas all over the engine and your face ...

on a empty carb, i had good success blowing out passages with carb-cleaner, not air.

syncing carbs is easy if you have the right tool. BUT, it's pretty much useless if you don't know when your valves were done last.
adjust valves first, then sync carbs. set carbs manually close to the disired settings, then use the sync tool to get them all to breath the same.
if one carb somehow lags behind the others, use the lowest one as your baseline and turn the others down to match ...

(IMG:style_emoticons/default/bye1.gif) Andy

[SGB]

I stick a grommet over the end of the carb cleaner straw and blow in from down at the hole where mixture screw goes in . I don;t have any advice- but what seems to be biting me is the alignment of the arms over the carps- one side is always opening more than the other through the rev range. Right now the car is balanced at about 3k rpm, but not at idle and not at higher rpm. My point I gguess is that the balance may need to be somewhere other than idle speed.

[SGB]

for the jet's, you wanna blow them out opposite to the gas flow. meaning, you blow into the little hole so the obstacle hopefully comes out the big hole ...


(IMG:style_emoticons/default/bye1.gif) Andy

I *think* the gas flows into the small end- I know for the main jets, the small, tapered side sits in the gas and meters the amount coming in. I guess the idles do something similar from the sides. Whattaya think? Maybe I'm getting all left handed on this...

[SirAndy]

I *think* the gas flows into the small end-

them how would the BIG chunck of stuff get through the small hole only to get stuck on the other side of the small hole and block the small hole until i blow it out the big hole?

it could just have flowed out the big hole all by itself ...
(IMG:style_emoticons/default/idea.gif) Andy

[Joe Ricard]

I just spray cleaner down through my "Jet Doctors" I pull the idle jets out and mixture screws out. Blow cleaner through top to bottom and then put a finger over the mixture hole and spray some more so I get flow through the progression ports.

Synching carbs requires lots of beer. Specially if you have CB or hex bar linkage. Basically you can adjust the mechanial advantage by changing the angle of the reach rods. Pretty much a PITA

Do this adjustment with the car off starting even on the idle stop screws the carbs should be WOT at the same time. You can also slot the hole inthe carb shaft linkage arm. changing the length of the fulcrum will make it all good (BUT YOU CAN SCREW IT UP EASILY) I had an arm break on me once.