CB Performance Throttle Linkage (Cross Bar, Hex Bar). Dual Carbs

This diagram may be useful for anyone with CB Performance Linkage (Cross Bar, Hex Bar).

Diagram available as a pdf from:

https://www.cbperformance.com/category-s/154.htm
http://cbperformance.net/pdf/DualCarburetorLinkageInstallation.pdf


The grub screw that holds the linkage arm to the Cross Bar is a 1/4 - 20 x 1/4 (UNC = Unified Coarse Pitch). You need an imperial/USA Hex key (Allen Key).

The Jam Nuts are 10 - 32 UNF (32threads per inch). The spanner to fit is 3/8" AF (across flats). the flats on the rod ends (Helm Joints) are 5/16".

Right hand thread jam nuts are available in the UK from https://www.accu.co.uk/imperial-hexagon-nuts/36769-HPN-10-32-A2

Left hand ones available from


https://www.mcgillmotorsport.com/3/16-unf-left-hand-threaded-half-nuts-pack-of-10-c-93-p-2731

The lock nut between the air filter base and the cross bar needs a 12mm spanner!

Velocity Stacks/Air Trumpets need a 10mm socket.

If you remove an idle jet holder and the jet remains in the carb, then don't panic. Get a Brass magnet (Bamboo bbq skewers work better than wooden cocktail sticks).

Details correct for my set up, but yours may differ slightly.

 

Good point about those awkward Allen key sizes Paul, metric keys just won't tighten up the drop arms sufficiently before they slip in the grub screw and round them off.

 

Thx Paul.. thats really helpful as I am just about to fit 34 ICTs to my type 4 & I've got the cb performance kit.
Do the swivel ball joints that fit into the air filter base plate (#3360) need to be cut down as mine seem very long.. or do they need to be kept long to retain the crossbar & just locked up with the lock nut?
Thx.

 

nice one Paul

 

Just screw the swivel ball joints into the air filter base and tighten the locknut, you shouldn’t need to cut the screw threads. The ball fits into the end of the cross bar which is centralised by the springs #3364.

 

USA product would be imperial sizes. I use that linkage with 36 twin Dellorto DRLA DB carbs, work really well, just be patient installing them

 

I'm glad @77 Westy has given you a proper answer as i have no idea.
Mine have been fitted since 2004 ish and I'm on dellorto carbs. Don't think mine have been cut

 

Cross bars are available in a variety of sizes, so i'd guess you need the correct size to fit.
If you have to cut anything to fit, id guess it would be the cross bar rather than the swivel ball joints

 

Unfortunately, you can’t cut the cross bar because the ends are counterbored for the spring. Well, you could cut them but the counterbore would have to be remachined.

 

I forget the spring fun, assembly is not the reverse of disassembly as you have to go brodling around the engine bay looking for the errant spring that went ping

 

But then you could actually fit bearings there that arent balls .. balls that grind into the end of the crossbar and go all wibbly that is.

Really needs something for centering left/right amd taking up engine width differences (heat expansion) with the springs then a proper radial bearing to take the sideways pulls on the bars.. a ball race or roller bearing. . Half engineered. . often made worse if something in the linkage is catching.

 

The engineering is sound but it’s cheaply done and I agree it should have a proper bearing - but that would add to the cost.

 

Incidentally, the VW Type 4 carb linkage is similar; at one end there is a ball in the cross tube, the other end the ball fits in a spring-loaded cup which slides in the tube. The balls are bigger but it’s not really better than the CB linkage, but it works – until someone losses the cup and/or spring.

 

They will be imperial sizes. Imperial allen key set costs about thruppence on eBay. Imperial fasteners ditto.

 

…as I found (should’ve expected for a US product) on my Berg shifter handle.

 

Yep, there is better stuff available, the air filters are good value, however.

 

This isn't a thread encouraging people to buy CB performance throttle linkage.

It will hopefully help those who already have this type of linkage.

No need to keep telling us how rubbish CB stuff is, unless you are planning on buying us all CSP bell crank linkages & fitting them for us.

 

I already have the cb linkage & this thread has been a great help to me Paul.

 

Lol. I haven’t in the past found CB stuff to be rubbish - one of the better brands I’d say, certainly better than EMPI.

 

Just one question... it says in the instructions (which are fantastic, really easy to follow) that you should coat the air filters in oil.
Is this really necessary? If do, what type of oil & do I need to literally saturate the filters, like paint the oil on & leave to drain off?
Thx.