On the top of each carb is a large, wavy edged, serated, or knurled knob. If you unscrew this by hand, you will be able to pull it out. It has a rod on the underside with a brass collar. This thing is a crude form of shock absorber & stops the internal piston, which is suspended on air pressure on one side, & partial vacuum on the other side, from bouncing up & down when driving. It also regulates the speed at which the piston rises when you hit the "power pedal".

Some blokes reckon it's the hot setup to leave it out, or at least run no oil at all. This is a total falsehood. Oils of difering viscosity are used to fine tune the opening rate & auto trans oil is often the recomended oil, but i used engine oil. This is a heavier viscosity & slowed the opening rate. The trade off is that my maximum possible acceleration was less than optimal, but i got great cruising characteristics & fabulous mileage.

L18_B110
The cam in my engine is described as a "Light Sports Grind" but no actual specs were forthcoming when i bought it from Repco in about 1983. I pushed the idle up to about 900 or 950 rpm & low speed characteristics were "quite acceptable" Like everything else, it's all a matter of balance, & i built my engine for my particular type of driving. It worked a treat for me & my particular application..