Dellorto accelerator pump

[billwill]

On Dellortos and Webers the so called choke, isn't a choke like on other carbs, it is a separate small carburettor with a preset very rich mix.

Earlier folk-lore on this forum said to start with:
Webers pump the throttle pedal a few strokes, no 'choke'
Dellortos Use the 'choke' no pumping.

Personally with my Dellortos I use full 'choke' no pumping.

[Donels]

Just to get back to the original topic.

To get the correct pump volume of 8 cc over 20 strokes the movement of the pump is actually very small. The pump plunger moves only 0,75 mm. As a starting point to set the adjustably rod this is about 2.15 mm movement.

[alan.barker]

I seem to remember in the past you needed about 6 or 7mm of the thread past the 2 locknuts as a basic setting.
Alan

[Donels]

A slight correction to my previous post, 2.15 mm gives a total flow of 8 cc. As this is required per barrel the flow should be 16 cc per carb so the starting point to set the adjustably rod is 4.3 mm movement from the point where the lever just contacts the pump plunger.