I can only get a spark at 1 pot & want to check the wiring to the coils. Can anyone advise re how the coils are wired?
Send me your email address via PM and I will send you a copy of my colour wiring diagram that will make everything crystal clear 
Mine has 2 x 6V coils wired in series, so that both plugs spark together. If yours is the same, I think any wiring issue would mean no sparks at all.
Ian
Simon, check the coils, HT leads and pug caps by swapping them before replacing the Lucas Rita box.
Hi again thanks for advice so far. I have fitted 2 x 6v coils in series & now have good sparks all round The left pot runs beautifully but the right pot still no go despite good spark & yes fuel is getting through. I have stripped & cleaned carburettor which looks to be OK. Do I need to do anything with the advance retard bob weights & springs etc? could this be causing the problem? I am running out of ideas on what to do. Thanks for any further advice
I could be wrong, but I think the RITA fitment means the mechanical advance mechanism is removed from the distributor.
Also a spark when the plug is out in the open air does not necessarily mean it will be a good spark under compression. Maybe try new plugs or swapping over left-right?
Are you happy with valve clearances, compression etc?
Ian
^ What he said - if one side is running it’s not that. Have you done what Chris said, tried swapping HT leads, also spark plugs, or try new ones, just to make sure those are eliminated. After trying to start it, is right side spark plug ‘wet’ when removed, if so then yes fuel is getting in, if no, then no it isn’t.
Hi OK I’ll get new plugs & HT leads as you say to at least fully eliminate them. Compression is good & yes the RH plug is wet. I’ll double check valve clearances. If that still does not work I guess I should look to remove the mechanical advance retard in case that is causing the RH pot problem. Ho hum I’ll report back once done. Thanks
If it’s got a Lucas AB11 amplifier then it’s a Lucas Rita system (actually made by Mistral Engineering) and if it’s a Lucas Rita system then there’s no mechanical advance retard mechanism. In any case wrong timing wouldn’t stop it firing I don’t think so think that’s a red herring.
Before another delay while you get the new leads and plugs can you not simply do as asked and swap the existing around left to right, it’s only to prove whether either of those is causing the right side not to work.
Mike I think I suggested swapping the plugs and leads I didn’t ask him to do it! You make him sound like a naughty schoolboy who hasn’t done his homework! 
Sorry I get frustrated while other people do stuff and I’m not sure if they’ve done it right.
Simon, sorry if it got lost in translation, when I said swap the HT leads and plug caps I meant from side to side, that will rule them out if the problem stays on the same side as before. Same thing goes for the plugs.
Best of luck
Simon, did you get to the bottom of this? What was the problem?
Ditto!