ok, for all you twin carb/throttle body experts out there....

I have a redline weber twin throttle body set up....got the linkage cross bar etc. from the same place...

I can't get this stupid thing to work correctly

I can get the right side to open and close fully and the other won't open all the way...I have switched everything around many different ways...even changed out the linkage cams...???

The linkages rotate into the center of the motor...flip the carbs around? so they rotate out?

the ball for the cross bar is down...if I flip it over, it will interfer with the air cleaner?? THis is driving me crazy!!! the only thing that I can figure out is that the holes are drilled off. one must be out further than the other..or the carbs need to rotate different amounts...???

I also can't figure out how to mount the crossbar to the front of the motor...I guess I could make up another cable stop...but???
I guess I can shoot some pics when I cool down...now for
thanks!

I think you would need to see a pic,
someone here will show you one for sure and if not,
tomorow I'll snap a pic. Maybe run a search in old posts.
Good luck
cheers
Joe

Couple of things to check. Does each one open fully if the cross linkage is disconnected? They have to work that way since when setting them the linkage is disconnected. If you hook one side up will it open fully? How about just the other side will it open fully? If the problem is when both are hooked up then the linkage is flexing due to some misalignment. The drop shafts should be as close to vertical as possible and make sure the carb cams or what ever they are called are on the throttle shafts fully and tight. I've had them come loose and rotate some on their own. Finally make sure the arms on the cross shaft are tight and not slipping when you work the throttle. Grab'm and see it they move on the shaft. Good luck.

Thanks for the insite....

yes, the throttles open fully when disconnected.
Yes the cams and levers are tight..

It looks like the cams (throttle levers) should be mirror image. They are not...looks close, but they are not exact mirrors.


Anyone using a easy to set up linkage? whos? this one looks good but is a POS...

I also think that I need shorter drop links..hmmm...got a couple of places to look for those...

ready to can the whole thing....

Get the CB Performance linkage setup. I think it's $100 or so from them. It's way better than the redline one.

My friend has a Redline one on his 912 motor, it works fine... But, it does look cheesy.

Later,
Tom

If you have a center piviot linkage it is a POS. Won't stay tuned as the motor changes temp and hard to get right in the first place. I have the Hex Bar linkage on 2 sand rails and one of the 914s. Esay to adjust and once adjusted, if you are careful about how you treat them they will stay in tune for you.
I did these in '92.
Joe

never had a problem with my CB linkage....

miles ahead of bugpack, redline etc....

i don't know the dial in for the center pull linkage. i presume there is one rod for each side. if the rod length run is shorter on one side there may not be enough travel to fully open the butterflies on the that side. the triad pictured is far and above the best linkage i've EVER dealt with. it DOES cost more than other, imho, inferior products, but you get what you pay for. btw, the thottle cable holder comes WITH the linkage. it may seem insignificant, but when the linkage from cb shows up without one you'll be cobbing something together.

k

I use the CB Performance Hex Bar Linkage setup on my twin Weber IDF 44 race car . In order to have the carbs in sync on opening and closing the drop shaft linkage must be in a 90 degree vertical position to the carb cam. If you look at the left and right side of the air cleaner base plates the attachment arms where the hex bar connects are not a mirror image, they are offset. What I did was cut off and reweld the arm to create a mirror image on each base plate allowing the drop shaft linkage to connect in a straight line to the carb. Problem solved, carbs in sync.

GB

staying in the verticle plane absolutely, is hard to achieve with regards to the down rods. use of hiem joints, like the triad, helps avoid the binding. i was pissed off enough when the cb one arrived without a t.c. holder. having to cut and weld a brand new item to optimise it's operation? the triad is a plug and play. powder coated out of the box.

k

kevin,

it took me 5 minutes tops to make a good throttle cable holder for my CB setup.
i like it alot.... the triad looks great too.

(Skline - post my engine picture)

i just bolted mine on after i opened the box. does the powder coating on yours match the cross bar? bottom line...use what works for ya. another thing i didn't like on the cb, was the goofy little springs that ride against the ball ends of the rods. the rod will travel a bit as the springs compress, imho. get the engine good and warm, and set the travel on the cross bar with the end bolts and jam nuts. done deal.

k

aluminum has no need to be powdercoated

i agree....both work...... both look great....

use what works for ya...

you got me there!!! it does like to be polished after it dulls a bit.

k

some pics of the set up...

QUOTE (crash914 @ Mar 23 2005, 06:27 PM)

some pics of the set up...

there is your problem! links need to be vertical! that pivot needs to be 4" higher!

not sure if you can see... but the pivot onb this is higher...and the links are vertical

my motor

You've got things backwards and upside-down. Turn the large gold piece on the end over so the pivot is above the top of the TB. I believe you will also have to flip the linkage end-to-end after doing this so it will fit.

After looking at it some more, I think you can just turn over the gold pieces on the end w/o flipping.

I need to get some more pictures...

When I flip over the gold plates...I can't install the air cleaners!!

Thats what got me thinking that my adjustable linkage is too long..

Stoooopid computer locked up last night and so I could not send any more...I will send some more later...thanks for the insite...

That linkage should work out just like the picture of the Candy Apple Red Mid-engine sand rail above.
Joe

I thought I had that bracket. Sorry about the sand, its off my othe sand rail. I like the background of this pic.
Joe

are the arms movable on the rod? if so, you need to slide them out to the point where they are just clear of the filters. that may help with the shallow down angle. when you go to dial them in try this. filters off, engine warm. back one idle screw off. use the other one to raise the idle to the point when the pulses don't effect the sycronometer ( i use 2700 rpm). adjust one of the rods to match the flow, or the ammount the throttle plates are open. turn the idle back down and turn the idle screw not making touching back in to just enough to make contact without affecting the idle. shut the engine down, have someone depress the gas pedal and look to make sure the throttle plates are fully opening. i have huge k&n filters, i had to use the "off road" variety of cb's base plates. the cross bar was too wide and i had to trim the length and redrill the ends. then i got rid of the pos and put on the triad.

k

QUOTE (rhodyguy @ Mar 24 2005, 08:03 AM)

are the arms movable on the rod? if so, you need to slide them out to the point where they are just clear of the filters. that may help with the shallow down angle. when you go to dial them in try this. filters off, engine warm. back one idle screw off. use the other one to raise the idle to the point when the pulses don't effect the sycronometer ( i use 2700 rpm). adjust one of the rods to match the flow, or the ammount the throttle plates are open. turn the idle back down and turn the idle screw not making touching back in to just enough to make contact without affecting the idle. shut the engine down, have someone depress the gas pedal and look to make sure the throttle plates are fully opening. i have huge k&n filters, i had to use the "off road" variety of cb's base plates. the cross bar was too wide and i had to trim the length and redrill the ends. then i got rid of the pos and put on the triad. k

how tall are your filters kevin?

i bet his arms bang on the fliter bases now that i think about it and that's why his arms are angled that way. mine measure 3 1/4"t x 5 1/4"w x 8 1/3"l. os measurements. how much $ was that redline linkage?

k

I'd add that your droplinks - are they right and left hand thread? meaning if you loosen the jam nuts can you spin the link and adjust the size, or do you have to remove the heim joint and spin it around?

If you have the right/left threads you can make minute adjustments to get the links on either side exactly the same, plus it is a helluva lot quicker and easier to make adjustments - move your slider arms closer to the carbs too.

not worth fuching with it...

buy a Triad or a CB linkage

-1. get the triad. oh, too much money . as compared to a set of auto cross only tires? in herb's picture the base plate for the filter is not installed.

k

This the way that I approch it. (---- Levers work best in the middle of thier arch.
Bring the rods to the middle of thier adjustment.
Make them the SAME length.
At half throttel the cam on the throttel shaft should be at 90 to the linkage rod
and the lever on the hex bar should be at 90 to the rod
the throttel lever to the cable should be at 90
and the cable should be pointing at the hex bar lever cable piviot point.
Every thing working in the middel of its arch, as close to 90 deg. as you can get it.
I have some extra al Hex-Bar stock, If you PM me with the length of yours I'll send you some, but you'll have to drill it yourself.

All good ideas guys, keep them comming....

The cost of this linkage was about $120.00 I think....getting old sucks...

you are also correct that I have to angle down the aluminum arm so the arm and linkage doesn't hit the air cleaner base.??/

here are some more pics..

nother.

other agreeing that it's not working for you i can't help with the linkage fix for that one. is that a cb f.i. set up?

k

as you can see from the picture above, the angle is to clear the air cleaner...

I keep comming back to the links are too long..

they are the right/left thread type...10/32 sized. I am thinking about re-threading the right hand part, then cutting them down so they are less than the 3 9/16 I now get...

Also the throttle butterfly linkage is not a perfect mirror image..that is off by I am guessing 1/8 inch or so...

What else do you guys need to see??

Sorry Herb But it looks like there is no room for the air cleaner. Duh!!! I don't know if you could shorten that much.
WTF was the manufacture thinking.
Joe

Joe, you mean swap the throttle bodies? So the butterflies swing out?

or the big aluminum arms??

or the cross bar socket??

The Socket goes up. Can you show me a pic of you air cleaner? I'm going to clean this before i post another picture of it.
Joe

Then I have a problem with the return spring.
Joe

problem with the air cleaner...

Flip the pivot....

needs to be above the carb body

O-tay did the flip...

And the return spring clip is pointing up.
Joe

last call

get a better linkage - CB

Not sure I'd toss in the towel just yet.

I do agree with you that the drop shaft arms look a bit too long in your setup.
One thing that I notice immediately is that you are using FI bodies
and not IDF carbs. It also appears that your distance from the center
of the butterfly shafts to the linkage plate is much smaller than on
IDFs. On 40 IDFs it is about 3.5" from the center of the shaft to where
the plate mounts. Your distance looks much less which may be
what is causing all the fitment issues. It might work just fine on real IDFs.
The CB one would at least give you more room since
it is flipped from yours and offers 2 height options; however,
before giving up you could go get/make some shorter heim joint arms/shafts and
some standoffs and see if you can get it to align with enough
clearance to miss the air cleaners. (See photo for using standoffs).
Lowe's around here has both heim joints stuff and standoffs.
Shorter shafts may actually make adjustment more difficult thought.

BTW, you can get it work properly without having your down shafts
at 90 degrees. (Mine aren't and both open together and fully at the same time)
What is VERY important is that if they are not at 90,
that their angle is exactly the same. If they aren't, the rotation rate on each
side will be uneaven and one will move faster/slower further/less than the other.

The easiest way to ensure this is to make sure that the linkage arms
are mounted on the cross bar at the same distance from each end.
I noticed in one of your pictures the linkage arm on the cyl 3/4 side
looked quite a bit further from the end than the other side.
When trying to adjust sides to match, if one butterfly isn't opening all the way,
simply slide one arm closer/further from the end of the hex bar.
One direction will give more rotation on the butterfly and the other
will give less.
You will have to adjust the downshaft as you slide it, but usually it isn't too bad.
Just keep slowly sliding and adjusting until both butterflies open
fully together and both fully close together.

As a starting point, I'd set both down shafts to EXACTLY the same lengh
and then you should be close and adjust arms on cross bar from there.


Hope that helps.

--- bill

Here is my CB unit...arms pointed to the rear of the car, simple bracket for the accelerator cable. My cross shaft is set in the lower holes of the cross bar mounts and the excess trimmed off. I agree that your fitment problems are due to the lower height of the throttle bodies. Return it and get a CB unit. DH

Wow...this thread is a great help to me...keep it going!!

Bill, the picture of the weber set up is exactly what view I needed....

I can see that there is an extension from the throttle arm to the drop link..this would be different on each side to allow the drop link to be exactly vertical.

The problem that I have ( I measured this morning) is that the pivot point for the hex shaft is off set one side is back 3" the other is forward by 1/2"????

I think that the problem is that the gold plates aren't made correctly...as was said, this is throttle body not IDF's

Thanks! all

I forgot about these, PM me your address and I'll send them along with some Hex-Bar stock. I hope you can use them.
Joe
Opps, forgot the pic

Pic

the last 2 pictures of yours nailed it herb. most kits come with the t.b shaft extensions, which will help. shorter drop rods and repositioning the arms one face forward on the hex rod should get you where you want to be. don't run the brackets upside down like in the one picture.

k

Yea, I am trying to get ahold of the vendor on the extensions...

Joe, thanks for the offer..If I can't get this figured out, I will take you up on it...

I just want the vendor to make it right first...

KOOL!!!
Joe