Idle on three pots

[promotor]

Hi all, just removed the Dellortos from the car. Got bored with messing on with them while fitted. Think we have found the problem. It was mentioned by Trevor early on in the post, regarding spindle being twisted. Seems the spindle on the back carb has been tweaked too far open at some point and has left the number three cylinder open and the fourth closed. The photo attached shows, if you can make it out, some WD40 sprayed in to the pair of them while stood on the trumpets. Clearly see that one is not draining through and the other has. There is no wear on the bearings at all, so all is well there. So...which way do we do it? Do we try and tweak it back on the open one, or open the closed one? Would seem to me to be easier to open the closed one? If it fails we just buy a new shaft, so not concerned about screwing it up at all. Many thanks to you all for your input. If we get it sorted will let you know. Rob

I'd take the spindle linkage nuts off - the spindle should have spanner flats on it. Try "tuning" the spindle with a pair of spanners working against each other. I'd do that with the throttle plates fully open so as not to damage the butterflies or the carb throats.

[Hawksfield]

Hi
Why do a bodge for the price of a spindle, you also need to check the condition of the butterflies. If they are as twisted you say somebody without any appreciation of carburettors has been at work.

[jasper2347]

Hi all, managed to tweak the throttle spindle after a bit of fiddling. Have also changed the carbs front to back, just in case the fault was still there. Set the balance and mixtures and the car runs on four cylinders for the first time since he bought it. Now sounds fit and well. Starts better from cold as well, as we now have four cylinders working with the throttle shut. Thanks to all who posted regarding this and we hope it may help others if a similar fault occurs. All we need now is better weather. Cheers, Rob