Tunning trip webbers?

[TBK1]

Ok i read alot of diff things on different sites, need some PRO advice/guidance.

Bought the nice webber sync dial, not unisync. double check me here!

remove all the connecting rods from throttle rod to carbs

-back out the idle speed screw so that it just touches ( all six)

-set idle speed screws at 1/2 turn past just touching

-set fuel mixture screw at 1.5 turns out to start (saw something about a 3rd progression hole!!!!)

-start engine and begin with each carb setting the mixture screw for best idle, meaning screw in until idle starts to drop then back out to best idle???

-then start adjusting each carb for flow(syncronizing ???) using the idle speed screw for each carb to achieve same flow at each carb while adjust all to maintain a proper idle speed approx 900 rpms.

- once all carbs are flowing same and idle is right carbs are Sync???

-reattach each linkage rod making sure it is right at the No Slop point with out changing the idle speed , tighned and done!!!

Well am I way off base or is this gonna get it Pro's!

Should have stated these are dcoe40's and the engine is 2.6 slightly modded, bored cam ext. headers.

[TBK1]

Damn Geezer you were right, 28 views! ???

[geezer]

Ok, I'm going to put it here. Tried to email it 3 times and it bounced back.

[geezer]

Here's some more

[geezer]

That's a typo on the conversion page, should be 240Z 260Z not 24 oz...

[geezer]

Had to downsize this one into 2 parts

[geezer]

What TBK was referring to when he said I was right, was the fact that tuning these carbs are difficult to explain on line and there would not be many about to try. The best thing to do is learn all you can and then do it on the roll.

[TBK1]

Thanks Geezer, pretty much what I had visioned,guess alot of us forgot our roots back in the 60's and 70's when we did these carbs blindfolded!

[hls30.com]

Ron,

Thanks, I needed that too!

Will

[TBK1]

UPDATE!

Ok Had time to play with these yesterday, ran into acouple of odd things per instructions above.

Ill start by saying that these have been installed and running for over a year with no significant probls. about 18MPG city. But always felt the werent quite right.

Backed off the idle speed screws until I had .006 cleareance between screw and stop (all 3 screws) then turned them in 360 degrees. set the mixture screws at 1 1/2 turns out from seat to start.

started enigne, running at 1400 RPM'S

backed all 3 spped screws out 1/2 turn took it to 900 to 1000 little rough idle

at this point checked air flow on all three sets and this is were things got odd.

2 of the 3 sets showed NO flow reading or low enough not to move the needle on the flow sync meter. one had about 5 on the scale

backed off the 5 to about 3 and barely tweekd the other 2 sets and boom had flow about 2. so took the high one down to three and the other 2 sets up to 3 then all 3 up to flow @ 4 on the scale with a stable idle about 850 to 900. all mixture screw adjusted to obtain best idle at at about 1 1/2 to 2 turns from seat.

runns pretty good and responsive, BUT what I found on all three sets is that I have a different flow on on the right side carb on each set meaning carb for cylinders 2 4 and 6, all were lower than left side of set, by atleast a half of the scale mean between 3 to 3 1/2 on the scale when left carbs were at 4.

Now if I understand things correctly that has to be an inssue with the intial bench setup between the 2 butterfly flaps????? I have never had these off and didnt do the intial setup, and assume there is no way to correct this or balance them equally when installed on engine!! at this tiem not a big deal just curious to know encase someday I want to play again and tear them apart.

Also would be curious to know what timing settings peoople using Unilite Dizzys with out vac advance are running. think I am at 17 or 18 static and 35 Total!! Mild cam! 30 over bore.

[geezer]

A lot of questions come to mind here. Do you know the history of these carbs? It almost sounds like they could have been set up for use on a car that does not have 1 intake runner per cylinder. As far as I know there is only the Datsun L series and XKE's that have individual runners. Short of tearing them down, which doesn't seem to be a priority if it's running well, you can linkage adjust them to better equalize air flow. It would be nice to have a look at the throttle plates to see if they were drilled to suit another manifold. If you can bring it from idle slowly up the RPM range smoothly to midrange and your plugs are still looking good, I would leave it until you want to remove them for a better look.

[jmortensen]

Pretty common for the throttle shafts on Mikunis to be slightly bent, making one hole in the carb read different from the other on the synch tool. I've read here or at hybridz.org about bending the throttle shafts to fix this problem. I seem to recall that it's fairly easy to fix, but I'm with geezer. If it's running well there isn't much point in spending the time to fix it.