the main difference, from what i can tell, is in the accelerator pump linkage and diaphram. i have the early style...


these carbs are in extremely rough shape and are currently going through a total rebuild right now.

as long as they're apart, is the late model perfered for any reason?


thx, n

buy the weber IDF update kit...

who's got it? i've been looking for it...

oh, you mean the CB kit...

this doesn't address the early style accelerator pump diaphram and cam system...

The main difference I know of is the accel linkage on the new style is adjustable without having to resort to a grinder or a welder. I've heard of several cases now with the old style Webers where the accel pump delivers way more fuel than required per stroke, and cutting this back will help both drivability and mileage. At least two setups I know of (including mine) also dribbled fuel out the accelerator pump while the engine was idling, until the pump cam was ground down a tad. Smelly idle and terrible mileage.

Other than that, there are minor differences on things like whether or not any vacuum ports are open, or blind plugged, or not there at all. I'd personally be happier if I had the new style, but the old style can be made to work. Of course, I'm switching to EFI as soon as I can make it happen (and I'm operating in Mueller time these days...)

I fixed that dribbling accel pump problem by using that other cb conversion kit--the one that has a new linkage plate with a round tension spring on each carb link plate--this eliminated my need for an external spring on each carb, and made the pedal MUCH more easily modulated, and it took care of the dribble, the real problem was that cross-bar linkage P.O.S.!!! I ditched that for a scat low-rider style linkage that bolts to the case split line-----wayyyy easy to set up!!!!

And it is outta the way--very clean install!!!!!!!!!!!

I have the round throttle arm springs on each carb, but still needed a third spring on the linkage to provide the *snap* close I wanted. I don't like throttles that stick open. I still had the dribbling pump on one carb.

I used the CB crossbar linkage because that's what everyone else said was the best there was...

"everyone" was wrong. The center pull twist linkage is much better. Infact I am scrapping a CB cross bar linkage from this motor I just built and will be running the Bug Pack bellcrank. Although modified quite a bit.

The reason you are having to do this is because you have one or both ball bearings on the ends of the shaft gone bad!!!!

The good news is because they are a spec ball bearing, all you need is a p/n and go to your nearest industrial supply store and get some more.

Another affair that could be giving you trouble is one or both of the butterflies have slipped in the pinch bar.

Hold them up to a light and look thru it--with the idle screw backed all the way out you should not see any light at all--if you do, that butterfly has slipped, but that is an easy fix!

Funny, I was told by "everyone" that the CB crossbar linkage was the best also...so who makes the centerpull twist linkage?

bugpack - is it decent, what kinda mods did you have to do?
scat - how expensive, is it any better than the bugpack?

anyone else?

What exactly don't you like about the crossbar linkage?

Thanks,

Tony

The best is the Triad. The CB is just aweful.

Matt

you got that right matt. finally something i can comment on.

kevin

triad is like 200 bucks tho....

the cb unit is the BEST for the BUCK. the crossbar never binds, and its not made out of thin sheet steel like bugpack etc.

It may be $200, but it is one of the best investments out there. I can't think of a better thing to spend $200 on. It would help every carbed car I've seen to date.

Matt

I think that I can comment.....

I just had matt over to look at why my car ran like s*it...mis adjusted carb linkage...I am running the redline webber linkage...matt thought it was just like the CB linkage....anyway, very hard to dial in both sides and not have a problem on either idle or WOT.....

I am now thinking about the Triad...

The Bug pack center pull linkage uses to different length arms. The pivot point is mounted off center of the engine case. You have to grind the legs off the stand and make it fit in the saddle beside one of the perimeter bolts. This will locate the pivot closer the center of the case. You will also need to weld two washers that you can fit to a much closer tolerance than the factory pivot hole. You will also need to relocate the binder bolt as well. Once that is done you need to build two equal length arms with good pivot balls on each end. once this is done you will need to build a stand to mount the throttle cable. ONce that is done you can go through the process of equalizing the arms and making sure that the travel is exactly the same on both sides of the carbs.

Yes it is labor intensive but this is the best linkage I have found. Until I finish my ball bearing pivot design this one goes on the last engine I built.

Brett...

Thanks for the writeup, doesn't really sound that bad...do you have a partnumber?

and of course, a picture of your setup would be great

Tony

Ok...I have found mention of a Kadron center pull linkage from both bugpack and on aircooled.net, both are around ~60 bucks, but no pics available...I am guessing these are the same.

this the one you are talking about Brett?

Tony

Yeah. I can't remember which one it is though. Don't know the difference. I will see if I can get a camera to take a few pictures before and after the install.

remember...the motor expands....

probably one of the many reasons why you sync your carbs after the engine is up to running temp...