Solex PDSIT twin carbs on 78 Bay - RH carb cannot adjust mixture

Good news. The mystery is (sort of) solved.

Reassembled everything this morning and made a new float pivot spring from a John West Mackerel lid. Still needs tuning, but fired it up and I can see on the Colourtune that the RH cylinders are firing with the idle circuit disconnected and the fuel shut completely off on the LH carb.

I took the time to examine the old gasket between the carb body and the throttle housing, and noticed that whilst the holes for the air/fuel passages were 'sort of' in the right place, it looks as though some of the holes were partially blocked. I spent a lot of time with a scalpel making the new gasket and ensuring nothing was blocked.

I'm going to assume for now it's the gasket that was blocking something, but the missing spring certainly would not have helped. If I don't find that brass spring on my drive over the next few weeks then maybe that was the culprit.

In any case, it's all good now, and I think the lesson for me is not to assume that pre-made gaskets in unbranded 're-build kits' fit perfectly without modification. Also glad I resisted the urge to buy a reconditioned carb. I already have duplicate plugs, leads, distributor caps and can do without spending any more money on parts that "might fix it".


Cheers all.

 

You thought it was lack of fuel to the idle circuit all through the thread - good work finding the culprit.

 

I wonder if the gaskets are almost symmetrical , and somebody put a left hand one upside-down on a right hand carburettor..

 

That's a possibility. Can't even blame anyone else as I fitted the rebuild kit myself. Er, on second thoughts it must have been a faulty gasket.

 

The non electronic cut off jets are much cheaper and you can spray carb cleaner thro to check unblocked. Used in kadrons /solexes. Eurocarb do sell them, they just don't realise it (doh). Other shops are available...