The best directions for Synching carbs & Adjusting Idle Mixture

Thanks for that Jack.  I'll stick it in my file for things I need to do to my Dells.

Frank

Sure, Frank---you are welcome.  When the day comes you will be set.   Jack

I gotta get a bigger file cabinet.......

Here's a ps.

All the instructions I have seen start with turning the idle mixture screws out 3 turns.  It is madness trying to keep track of where that 8 sided idle screw is on the way to three turns out.  

These screws have 6-8 flat sides so mark one of the flat sides with white out after cleaning it--I used laquer  thinner for that.  Now you have a reference and you can watch for that white mark to come around as you count your turns.  Otherwise you will never know when a complete revolution has been made.  This works for #1, #2 and #4 but not for #3 (on mine) because you can't see the idle screw!  So rather than marking the screw, mark your screwdriver with the white out and use that as your reference. Be very careful to not let the screwdriver slip out of the slot so you don't loose your place.

Get a 1" "stubby" screwdriver for these adjustments. 

Last thought--the Empi reference omits the "3 turns out" and on line #12 says to start turning the screw in until the RPM fluctuates. The only way to know that the engine is fluctuating is to start at 3 turns out where it's running smoothly? (rich, but smoothly).

There is a motivational film of Coach Vince Lombardy speaking to new arrivals to his team.  His first words upon holding up a football were to say "gentlemen., this is a football"  I guess he felt that basic is best too.  Sorry for the length of this.  Wish I had this info 7 years ago when I got my Speedster! 

Gordon----me too on the file cabinet!

I' m newer to the Speedster set so I only have a 'file folder' as of yet. Should I be shopping for something larger to keep my docs in??

How big is your garage?

…or buy your own cloud server for home use!

Cloud? How do you buy a cloud?

Cloud? I don't have time for new tech--

....I have to go adjust my (old tech) carbs.

Lots of old people know how to use the cloud....

That's her dog silly!

    Jack,

    Even a 1" stubby is an aggravating experience when tackling #3 (Weber 44) in the VS. I can barely squeeze my hand in sideways but can't move my fingers!...and of course can't see either.

    Somewhere I picked up a neat, compact, reversible ratchet screw driver (HF?) with six replaceable bits that's only 1 1/2" wide with a slim 4" 90 degree handle with a thumb activated wheel to reverse rotation...handy little bugger for #1...but still frustrating for #3

      I'm now seriously thinking of a 'porthole' cut into the wheel well as I did for #I & 3 spark plugs...easy-peasy access!

     Yesterday I had the giddy (and white knuckle!) experience of right seating an exhilarating cruise in Danny's 550...(never imagined a tuned type1 could possibly pump out that kind of torque and acceleration)... but the enviable impression was the accessibility he has to the entire engine. Carbs, plugs, the whole kit and caboodle...It's as if it's mounted knee high on a non rotating engine stand!!! 

It's even better if you drive it, Carl.  Hoooolyyyyyy  SHI..........................!!!!!!!!!!!!!!!! 

Lane,

Danny offered me the driver seat coming down off the mountain on a Monte Carlo like series of 180 switchbacks...No way was I going to be responsible for getting that 550 back to the valley!!!

I was content to hold on tight and squeal with delight while he fish-tailed through some of those tight curves.

Carl--remove your #1 air filter and tou can see that screw.  Same for #3 but you don't see very much of it!  That's why I mark the srubby handle rather than that #3 idle mixture screw.

#3 needs to be done right too---I read that that's the hottest running cylinder so too lean is gonna make it run even hotter.  

    I'll give it a try Jack, but I'll have to hacksaw about an inch off the stubby screwdriver handle...at 3 1/2" overall it's still about an inch too wide to manipulate in that narrow #3 space.

    That small reversible ratchet I described is only 1 1/2" wide but it doesn't give me a 'direct feel' of contact and pressure...and without being able to clearly see what I'm doing it's a recipe for frustration...but the opportunity to coin new cuss words!

Carl--I have a VS too and a Type IV engine which may even be a bit wider that the Type I but I don't know for sure.  The 1 1/2" stubby gets onto the idlecrew just fine. I wonder why you have less space at the #3 idle mixture screw than I do??

Jack, I wonder too!

I may not have less space...just fatter hands with less nimble fingers, and a lot less patience.  

When I had the JPS (pan-based, and REALLY tight at #3), I brazed the tip I cut off a #2 screwdriver to a nickle. Worked like a champ.

Art--I have both those tools but using them, you cannot keep track of the number of turns you are turning the Idle mixture screws out to begin closing them to find best idle. 

Only Stan Galat would think of brazing a screwdriver tip to a nickle!  Incredible.  And only Stran Galat could actually do the brazing.  I'd buy one of those dudes from Stan only I don't know how I'd mark the thing to keep track of the turns.  How do you keep track, stan?  What a great idea for a tool.

Cut a slot in the nickel to mark the spot, or grind a flat. Anything to give you some orientation.

I don't have the tool any more, because the JPS had Webers, which had round-headed idle adjustment screws. They required a screwdriver to adjust. Blessedly, I no longer have the car.

However (and blessedly for you), every set of Dellortos I've ever had have a hex for the idle mixture screw, with a slot cut in it. You shouldn't need to use the screw slot at all-- I use the hex. I adjust mine with a small box end wrench (8mm, I think). It helps me keep track of how much I've turned the screw, and it doesn't slip off easily (like a screwdriver does). In a tight spot, you might only be able to go 1/4 turn at a time, but you'll never, ever get lost. It also has the advantage of being really, really short-- shorter even than the nickel.

I use a modified 1/4 in. drive"socket" on my Dels.....   Ran a small machine screw through from the hex side and bolted on a fender washer with a flat ground on one side...(for orientation.)  Used locktite and a nylock nut to insure the assembley...

Smart. Just like your pole of VW horns to entertain your neighbors that time!  I think I contributed a couple of ths horns!

Jack, I would NEVER richen a full turn after lean peak on Webers or Dells.  You are wasting fuel and washing the cylinder walls clean with gasoline. I realize Dells have finer threads on the mixture screws than Webers, but richening that much is not a good thing. Sometimes I richen about 1/16th of a turn from lean peak rpm on the Webers but not more. A quarter turn on the Dells sounds OK, but you could probably leave them alone at peak.

I never count turns, I just set each cylinder at peak rpm and leave it there. I'm unsure of the recommended/usual number for Dells. Stan? About 1 to 1.5 turns out on Webers is indicative of proper jetting.

Glad you found a synch tutorial that worked for you Jack, did you ever read mine? It's posted on here.

Carl, glad you stopped by, great to see you!

"Listen to your carbs, grasshopper. The sound will enlighten you."

-Danny "Kung fu"  Piperato

"I never count turns, I just set each cylinder at peak rpm and leave it there. I'm unsure of the recommended/usual number for Dells.  About 1 to 1.5 turns out on Webers is indicative of proper jetting."

True, but it depends on the jetting, carb size, yadda-yadda.

If you're running your jets a tad rich, the mixture screw won't be out as far.  Mine peak around 1/2 turn.

I only count turns as a static setting on the bench, just to get it "in the ballpark" so the damn thing will at least start.  Once it's running (which will happen again for Pearl, someday, I know....) I use the "Danny Approach" of watchful listening and forget about turn counting.  On my Dells (I love my Dells......Have I ever said that?) the mixture screw heads are hex and big enough that I just turn them with my hand.  A challenge if it's hot-soaked, but do-able.  

Otherwise, I use one of those little key-chain screw-driver disks from SnapOn or Craftsman - looks about the size of a quarter and has an edge that works like a screwdriver.  Often they're given away at shows or come as part of a tool set.  Just pop it into my goodie bag behind the seat so I know where it is.

Didn't Ben Afleck get thrown out of a Vegas Casino for counting turns?

Good tip Danny--thanks.  

I know you dnn't count turns but what would you estimate is the number of turns out from seated, on average, you see for Dells when they are peaked?  Not that they can ever be set by using such a number because each carb has it's own sweet spot---but a ballpark average? I know it's not one turn and surely not 3.

Thanks!

I'm going to go out on a limb and make some big/broad statements, which are based on doing a lot of things wrong before I figured out what works well for me. Your mileage may vary.

Of all the things that can be done to a carb (venturis, main jets, air-jets, emulsion jets, idle jets, accelerator pump jet and adjustment, adjusting the mixture screws, and syncing the carbs) and the two things that most people mess with (setting the mixture screws, and syncing the carbs), the mixture screws matter the least of all.

If you've picked the right sized carburetors for your engine, the sync is probably the most important adjustment you can make, followed closely by the appropriate idle-jets. All the big-boy drag-race types obsess about the main-jets, but the only place they are "in play" is at wide open throttle (WOT), and even then in a real-world situation the accelerator pump squirt messes with the mixture for probably 2 or 3 seconds (depending on how it's adjusted). Big dyno numbers are the result of nicely dialed in main-jets. Most dyno tuners don't even think about eh idles, and guys wonder why their engines run like dogs on the street. It's mostly because they are generally jetted at least 2 sizes too rich in the idles, and one or 2 sizes too rich in the mains (for the "real world").

It's the TRANSITION that matters-- very light throttle moving into WOT. That's all about picking the appropriate sized carb, fitting it with the appropriate sized idle-jets, and GETTING THE SNYC DIALED IN. Transition is everything. It's also where Dellortos shine.

Regarding the mixture screw adjustment: it's nice to get them "oh so fine", but think about what you are really doing. The only time the screws come into play is when the throttle plates are closed and the engine is just sitting there idling. It's nice to be able to walk away from the car while it's warming up, and to not have the carbs "load up" while on the idles... but in the real world-- if you are jetted correctly and synced properly, getting them "close" is really more than close enough. I go 1/2 turn out from best lean idle, and it works fine. I'd be willing to bet that there is just about zero difference in fuel mileage between an engine set exactly to best leak idle, and one that is one turn out.

To further inflame the faithful... it's hard to overstate how much nicer Dellortos are than Webers. I know Danny disagrees with this, and it is possible to get Weber IDFs (And EMPI "Weber IDF clones") to work well-- but everything is easier to work on in DRLAs. The jet-stacks are both on top (where you can get to them), the mixture screws are hex-headed (so a wrench will fit on them). Most importantly, the DRLA transition circuit is the miracle of the mechanical age-- it's hard to imagine how something as crude as a "controlled fuel leak" (a mechanical carburetor) can work so well.

IDAs are a whole 'nuther thing that I've never learned-- but they have some really nice features, once you get them modified with the extra transition holes, etc. Maybe 2% of us have them, so I'm not addressing them at all.

In summation: Jack had really good success with his adjustments because his carbs were already the right size, and jetted correctly for his application. He was super-careful with the two common adjustments he made, and the instructions he gave were very plain and well written. There is a way to get the mixture screws even closer, but it doesn't matter anywhere nearly as much as most people think.  

Great post, Stan.

Stan, I don't have Dellortos so I have nothing to compare my Spanish Webers to. I'll take your word on them as I value your opinion and your expertise and, of course, you're my buddy.

Trying to score a set of Dells is difficult and expensive. Parts are harder to source and info on them is more cult driven than comercially available.

Webers, on the other hand, are widely available, even the Italian versions pop up with regularity on Samba. Reprops are becoming more reliable. Question - why isn't anyone reproducing Dells?

My webers were terrible when I first got them and, of course, I didn't have a clue on how to adjust/maintain them. Fortunately there is a plethora of DYI literature available, most notably Mark Harney and Danny P, to name a couple.

Once they were torn apart, cleaned and reassembled, fine-tuning was easily performed by changing out the venturies, idle, main and air jets, adding the hex-side idle jet holders and purchasing a German synchrometer.

Again, I have nothing to compare them to, but my Webers run very well now. There is no transistion hesitation, no hesitation whatsoever,  smooth idle and excellent acceleration.

I will add, however, that there is a significant learning curve to understand Webers - they're not for slackers or pussys...

Terry,

I read somewhere why Dells are no longer produced, and it seems logical.

Dellortos were produced as reliable, smooth, high end carbs for high end, mainly Italian, autos.

When FI began making big inroads in engine configurations there simply wasn't enough volume to warrant their continued production....That's why they're now so difficult$$ to obtain. 

I have 2 48 Dells in the original boxes never used waiting for a good home. Bought them in 2004 from a guy who bought them from Jake Raby but never used them. Thought they were going to be for Spyder #3 with a Type 4 but I built a Caterham instead.  Used FI with 4 throttle bodies for the Caterham.  Then I got the FI IM.  Might use them as bookends in the man room.  They are beautiful.

I can't remember anyone ever saying that Webers are "Bad", just that they are harder to make run "right" than a Dellorto, for all of the reasons Stan stated up above - they are simply much easier to work on, either on or off the car.

Another plus is that Dells seem to be far less prone to idle jet clogging - a really BIG thing for most of us, it seems.  In the 16 years I've been running my Dells, I have had exactly one clogged idle jet, and that was fixed in ten minutes because the jet holders are, as Stan mentioned, up on top of the carb and easy to get at.

Everyone in the British world complains about how bad SU's are to get running and set-up right (Believe me, you Weber guys got nothing to complain about).  I had three of them on my Austin Healey and set them up using a book I got at a car show (sorry, I can't remember the name of it) and, once I got the oil level right (they use an oil damped piston to vary fuel delivery - they're British, after all), they ran great and I never touched them again for five years (then I sold it).

I've got a set of Dellorto 48 Tri-Jets-- which I paid over $1K for, then had rebuilt at BlackLine Racing (for another $400). I ran them for a while on my 2276, before I realized that I'd rather give up 10 hp on top to gain really, really nice throttle response.

The "re-born" 2276 will have a set of 45s. I'm a big fan of keeping it real.

I need to sell the tri-jets... but I can't seem to let go of anything in my stash. Who knows when a guy might build a 3L Type 4?

Oh boy! Here we go.

Stan and I have been talking around T4 for a while.

Why stop now Emperor? You're already part way there with those 48's.

That is a GREAT question. Why reproduce Webers, and not Dells?

Because the VW hobby is a little backwater in the great automotive sea? Because there were 100 IDFs built for every DRLA? Because people are more familiar with 'em. I have no idea, but it is strange to me.

Opportunity?