Float height

[Bambino126]

When you set a carburettors "float height", are you setting the gap with the float in the upper or lower position? E.g 'hanging down' or 'lifted up'?

I think I may have done it wrong, and now I'm having trouble starting....

[Pete126]

Hanging down resting on the inlet jet/valve

[Bambino126]

I see - so you take your measurement with the fuel inlet valve in its "closed" position.

Ta

[Bambino126]

On my float it has a welded construction seam running all the way around it about 2mm thick.

Should the gap be from the highest point of the seam up to the cover, or from the floats body up to the cover?

When they tell you that your measurement has to be accurate to 0.25mm, a 2mm seam makes a difference!

[Pete126]

Measure from the flat point of the float as the diagram not the weld If you cut a piece of card to 9.5mm it makes it easier to set the gap

[Bambino126]

Cool thanks.
I actually used a 10mm drill bit and it worked well.
I dug out from my spares box a much better float aswell - it had a much less pronounced seam, and it was the correct weight. Did you know they are supposed to be 11 grams?  I didn't!
Did lots of forum searches to see what others had done. The other float with the course welded seams was 13g.

The other thing that's not clear is how far you allow it to hang down when the float valve is in the open position e.g. when petrol is flowing. Maybe its not very important.

On the Polish carb they give you the float height in the "fully up" and "fully down" settings - 8.5mm and 13mm but with the Weber you only get the upper one.
I measured the depth of the carb float chamber on the weber and worked out that the float would be resting on the floor at a height drop of 15mm so I set my float "fully down" limit to 14mm. The thinking being that if they wanted your float to actually rest on the floor they wouldn't have gone to the trouble of making a "stop" for the float to rest on. Don't know if that's right but I've put it back together and its starting and driving well.