More help with Carb rebuild

Looking for some additional help with my carb rebuild for the Seca.

Here is my question, When I assembled each carb individually, there was close to no light that could be seen between the butterfly and the carb body on any of the carbs...once the rack was assembled both #1 & #4 show no visible light...#2 has just a sliver, but #3 is open much more than the others (width of a business card). Is this normal, and should I proceed with bench sync?
Mind you, all adjustment screws are backed off to the point they are no longer affecting movement.

 

#3 is adjusted via the big knob. It has no adjuster of its own.

 

what you want is all 4 butterflies shut with no back light at all..
light means air and you will have an idle problem..

 

#3 can't close anymore because 1 or 2 or 4 is holding it open. turn your idle knob to open 3 just a bit more then do the sync screws to make 124 look like 3, then back off the idle knob and tweek the sync screws till they all look like this

 

+1

If they all were the same with the screws backed off there would be no need for the screws.......

 

Tuning of the Carbs should begin with Bench Syncing the Rack to the Number-3 Carb.

Lube and "Exercise" the Idle Rod and the 3 Sync Screws.

Use Strips of 3X5 Card to Bench Sync the Rack with Throttles Closed.

Getting the Bike to IDLE on the Pilot Circuit is the starting point in getting
dialed-in!

 

Thanks to all.
Pollock, if I understand correctly I now need to adjust #'s 1,2, and 4 to the position #3 is currently in...this in turn(no pun intended) will allow #3 (and all others) to now close down completely at which point I can readjust all four in unison using the large idle adjust knob?
Thanks again...perhaps this "remedial" carb tuning 101.... But it's all new to me.
P

 

I think you have it but turn in the idle knob till it opens 3 a little more.
Start from there. You'll notice the 1/2 screw opens 1 or 2 depending how you turn it
and closes the other. The 3/4 screw is trying to do the same but the idle knob is holding 3
so only 4 moves. Then 2/3 will move 12 as a set with 34 but 3 is against the idle screw so only 12 will move, now back off the idle and fine tune it, same way.
When your done the idle knob should let them all close completely at the same time.
Spin them screws buddy, It's easier to do than think about.

 

Pardon the hi-jack but I will be going down this road in a couple months myself. So, the goal here is to match all of the gaps on the butterflies. Is .008" (business card) thickness optimal?
I have access to a variety of shim stock/ precision feeler stock. Stainless and plastic - I'm guessing that avoiding the stainless steel is probable wise.
So I can go as low as .001" or .002". . . Or does it not matter what the gap is just so everything is the same?

 

From what I have gathered, you want to "sync" the butterflies as close as possible while on the "bench." This will allow you to start the bike and use the idle adjustment knob to idle the bike as you perform a vacuum, or a running sync, which will fine tune the butterflies and supercede the "bench" sync....of course, as Fitz always reminds us, your valve clearances must be in spec prior to the running vacuum sync. Once that is done then it is on to the colortune turning of the air/fuel mix on each carb and readjustment of the butterflies with the vacuum sync...

 

Someone please correct me if I'm wrong, but it's my understanding that you want to bench sync all carbs to approximately the same thickness (a business card or index card works well because it can conform to the radius of the carb throat) and then use the idle adjustment knob to back all four carbs down to just a sliver of an opening (based on Pollocks picture...just past those two small orifaces at the top of the throat.).

 

Someone please correct me if I'm wrong, but it's my understanding that you want to bench sync all carbs to approximately the same thickness (a business card or index card works well because it can conform to the radius of the carb throat) and then use the idle adjustment knob to back all four carbs down to just a sliver of an opening (based on Pollocks picture...just past those two small orifaces at the top of the throat.).

 

Stumplifter, you can use shim stock but it's kind of awkward, and your trying to fit a flat thing(shim stock) into a curved space and if you leave two shims in the bores you need three hands to work two shims and turn the screw. if you use those holes on the top of the bore on the engine side,you can see two carbs almost at the same time and have a hand left over to hold a beer.

 

The process begins after your Valves are in Spec.

Bench-sync with the Throttles virtually closes lets you set the Idle using the Pilot Mixture Screws supplying the Air-Fuel Ratio required to have the Plant Idle without being Leaned-out by Intake Air and/or being reliant on Main Jet supplied Fuel.

Once the Bike Idles on its own, ... additional (but not much more) Richness enables the Plant a smooth transition from IDLE -to- OFF IDLE.

Too little "Supplemental Richness" will cause a Hesitation until Main Jet Supplied Fuel takes over.

Too much, ... you'll Bog-out.