Carburattor Connection To Throttle Cables?

[mwoods666]

Hello All,

I have recently finshed a head rebuild on a car that has been off the road for a year, Everything is back together carbs are overhauled and reattached, currently the throttle coupling between the carbs is rotating downwards. When I come to attach the throttle cable, There is a guide for the same on a bracket at the top of the air box (carb side) However if I use this as a stop location for the outer cable, the remaining inner cable is pulling upwards, in the opposite direction to the direction of rotation of the throttle coupling.

I have tried reversing the throttle coupling, to turn it upside down, in this format it catches the carb body and does not fully open.

The workshop manual is silent about this aspect, however all of the photos I have seen show the throttle cable attaching to the carbs from above.

Could someone explain the correct, position method of attachment or position of the throttle coupling between the carbs?

If someone could take aclose up of their own car and e mail it I would appreciate it the address is [email protected]

Thank you in anticipation !!!

Martin

[Foxie]

Martin,

Would it be possible you may have the airbox inner part upside down ?

The inner cable is fixed to the airbox bracket below the carbs, the throttle (Weber) arm is attached to the outer cable and moves downwards.

Sean Murray

[type26owner]

Martin,
Assuming you have Webers the sheath is attached to the throttle shaft lever and does the opening of the throttles. The cable does not move and is secured to the bracket extending off the airbox rear panel. The linkage has a clevis which takes a special bronze pivot pin that has a through hole with counterbore pocket that accepts end of the sheath. A slot which just fits the cable diameter on one side of the pin allows the cable to be easily loaded. Assemble it so the slot faces the closed end of the clevis and the cable will be captured and not become detached at the worst moment possible.

One real problem with this arrangement is when the cable and sheath is operated the sheath will try to align into the shortest configuration possible. Unfortunately this lifts the sheath regardless of whether it's a LHD or RHD setup and causes it to rub up against the bonnet with quite a bit of force. Just look for the wear pattern on the bonnet and the sheath for confirmation. Have someone depress the pedal and you push the sheath down to the level of the inside surface of the bonnet to experience this effect. That additional friction will cause the tactile feel of the happy pedal to be sticky, imprecise and heavy feeling. Adding a few more horsepower or feathering some off will be impossible at the level you need to be able to do it when going at 10/10s in a powerslide. It's all about being able to position the feather-light pedal to the millimeter level with fantastic control. Adding more springs onto the throttles is a surefire way to go slower on the track. There are motorcycle cable lubricators which will inject lubricant through the cable and that will help reduce the binding of a dry cable a lot. The best arrangement is to build a low friction guidance rail which restrains the lifting of the sheath and keeps it from contacting the bonnet entirely. Suppose you could grease the bonnet instead.

[1964 S1]

Good call Sean, I'm wondering if you were right...

[type26owner]

Nope, it's not possible to mount the airbox backingplate upside down. The hole spacing is wrong for the studs projecting out of the carbies and it can't be done.

[mwoods666]

Thanks,

It turns out that the rear of the airbox is fitted upside down (I assume previously modified by someone given the extra holes that exist to position the bolts from the carbs)

By reversing this and blocking the additional holes, all should work fine,

Thanks again

Martin