lets say the newer ones.. noted by their cast enrichment block offs.. still stated as made in SPAIN..

Not to long ago we went with a set of these from a place on samba that sales them new for 450..
a decent deal if you buy the CB intake/linkage/ air cleaner kit.. for 150 dollars.. plus a set of Velocity stacks
the aluminum ones like the ones for Dells.. at 28bucks for the set (unlike the steel ones for webers at 44 dollars a set)
makes for a setup cost of 630-650shipped total over what CB sells for 780 (less V-stacks)

So... thinking we made out good.. we decided to tear them down and clean them out and base line set them up
before install.. Check/set float level...check seating of jets.. check seating of secondary ventury against the wall..
a nice little polish with scotch brite to the Venturie while out side the carb.. (chucked up in a lathe would be sweet to kiss and shine.. but I use my padded flooring to roll the venturie on with the green scotch brite on the inside-my cheap lathe ) -check for throttle shaft play and general health.. after all said and done reassemble and base line
for install..

SO FAR SO EASY.. right..

well we get his motor ready for break in... and get that done .. now ready for engine stand tuning.. basically at idle
smoothness and lean best mixture adjustment..

NOW the NEW WEBER Problem walks in the room and says "what up?" Who knew it was something to look for..
apparently (per CB there is a run of webers that have loose mixture seats) (something even Donnie ran into on a old used set) so now.. we have popping at idle that we can not get rid of.. I tried a few different things and mainly had them some what under control with a hair of intermittent popping.. but even with my messsing with it on the stand I had a seat fall out.. so I loctited it in place.. let it set up for a night.. since I was finished for that night anyways..
seemed to do "OK" but with the mixture screws so easily wedging into the seats it pulled right back out anyways..

The owner drove it home and tried to address the popping himself.. and ended up pulling them all out.. BASICALLY the combo of loose seats(or casting drilled out too large) and the ability of the seeming softer steel mixture screw that seized into the seat with minimal effort .. that is why he was able to remove all seats from these carbs..

WHAT A MESS... so the two of us pried them apart one holding the mixture screw and one loosely holding needle nose pliers we got all the seats off the tips.. and decided to order
http://www.cbperformance.com/ProductDet ... tCode=6381

THIS IS A COMPLETE WASTE OF TIME.. even with speaking with CB tech support they say the say thing.. their tool they provide must be sanded down as the O.D. is too large for I.D. of the mixture screw galley.. and their replacement tips are too large to fit down the hole.. WTF!!!

after figuring this out... and seeing how the the original seats basically just fall out now.. we decided to JB weld them..a very small amount just to the O.D. of the seat just were it was going to seat in the casting .. and press them in with the end of a properly chosen sized drill bit.. and let them sit over night for the JB to cure..

NICE!!
we also decided to pick up another set of mixture screws.. because even the lightly seating of the original ones into the brass seat left a ring on them .. too soft I tell ya...

with the combo of cured JB and new mixture screws.. everything is up and running..smooth as butter..

A rough start to a happy ending.. based on poorly designed/assembled/ QC /what ever product that we should of not had to worry about on items like this..

Just goes to show you.. these days you have to check EVERYTHING .. I mean EVERYTHING..



PASSING ON WHAT I LEARNED(AND KEEP LEARNING ON WHAT TO LOOK FOR) with carbs..

seperate but equally important issue.. on older cam style accelerator pump style carbs.. even IDA's you must inspect the cam for smoothness and the wheel for it's ability to rotate evenly and smoothly.. as any hiccup could cause a little extra pump while cruising in the throttle position of the problem.. in my experience it caused the AFR to jump rich and the motor stumble accordingly.. ah FUN STUFF...


NOT AN EXPERT.. I so wish I were.. so if any one has something else to add.. or modify please ..please do so we all win with correct information..

While reading the part of the description of the loose seats, good ole JB Weld came to mind

Thanks for the post, when I get back home I am going to give my EFI a big hug

Nice info, Tommie.

I have a nagging pop at idle, and a little rough, too. As soon as I crack the throttle, it smooths right out. I'll take a close look at mixture screws/seats.

Very good detail write up, I especially like the part of the tool description that states:

Did your mixture screw seat come out or is it loose? Then this is the kit for you!

After years of adjustments of the mixture screw and material deterioration due to age, this has become an all-too-common problem. CB Performance has re-designed the seat to include a set of one-way barbs that keep it secure for many years to come.

The kit includes an installation tool and four new seats to upgrade a pair of IDF carburetors. Get those broken carbs off the shelf and back in your ride with this quick and easy fix.

Yea.. after Speaking with Aaron at CB and having him go get some hands on confirmation.. he said they really should
revise their description and add "AS A LAST RESORT"