Dellorto DRLA40 carburetor non linkage return Issue.

27th October 2009
I had been noticing that my left carburetor was not returning to its stop since the rebuild process for the turbo seals whilst I was installing the new linkage kit. I was not entirely happy with the shaft when I put it back during the turbo rebuild and it appeared now I was right and the non return issue on my left carburetor was due to the spindle being bent. This resulted in the shaft rubbing in the carburetor. The only solution I found was to renew the shaft. Its quite tricky to do as you need to be comfortable with stripping the carburetor. The best way to do this is to photograph each stage if you haven done this before. You need to remove the paraphernalia on the top of the carburetor Air cleaners or trumpets. There are 4 screws on the op of the carburetor that hold the float cover on. If you remove these you will most definitely need a new gasket so don't skimp. With the top loose gently remove the top carefully as the float is underneath put these items somewhere safe in a backing tray.

Next remove the two screws either side of the carburetor this locate the spray bar it only goes in one way make sure when you take it out you recognise this. The screw is usually held with a locking nut. With this out the chokes can be removed sometimes these grow in here and will need carburetor cleaner to get the loose and maybe a soft tap. Again look at the orientation how the come out. Record everything

Next remove the nuts on the spindle and remove the control arms these must go on the right way round. Its important that you note which side the longest part of the spindle protrudes from it is imperative it is put back exactly the same for your linkage kit to work.

Next turn the carburetor over you should see the two butterfly valves two of them in each carburetor throat they are held with two brass screws which are peened over on the back so they don't fall out. Once you have the screws out you can twist the spindle vertically so that the butterfly can be removed by sliding them out of the slot. Repeat 4 times noting which way round the butterflies come out and which hole and which way up they will only come out one side. With the butterflies out Put one of the spindle nuts back on the spindle and use a soft rubber mallet like a camping one to remove it. The bearing may come out too don't worry. Use a thin screwdriver to drive it all the way out. You can knock out the bearings whilst your there and remove the plastic covers with a small watchmakers screwdriver and grease the bearings replace the plastic cover.

Put it back is same as dismantling it. Make sure the new shafts the right way round (imperative) I used a couple of sockets or tubing at ether end of the spindle to drive the bearings into their correct seating.

The butterflies can only be inserted from one side of the spindle they wond go in from the other side. Use 4 new brass screws for the butterflies. Peen them from the other side once their tightened by putting a screwdriver across the back of them and tapping the screwdriver with a light hammer ensure you support the shaft underneath with something so as to not bend it again.

Now I did this I now need no springs at all. A carburetor schematic can be found on the www.dellorto.co.uk web site you can buy parts here or on ebay.