Its better now you have provided some extra info.
. Sometimes after carby overhauls and things, because the denser fuel mixture, or volumetric increase in mixture entering the cylinder is what is should be, the old blocked up carby can make it run lean or rich and underlying ignition problems can then be made more predominant. When doing the timing I would do it in 2 degree increments and then test drive. Not sure why it would only happens on right turns so you were right in assuming it could be float related. Remember that higher octane fuels like LPG and 98 burn slower so need more advance (with stock compression ratios), so I was assuming that you were running higher hence the advance is not enough.
One other thing it could be is you base idle mixture could be too lean, so under partial throttle, when you are turn the roundabout, or feathering the throttle lightly, the transition is now requiring the base setting to be a bit richer than previously so try
Before doing this remove vacuum advance line (if you have one).
1. (Using the lean drop method) get your idle screw and wind it in slowly until you get the engine to slow in revs, then back off until you get smooth running. If idle is a bit too high, set it correctly now as a base setting. This will richen the mixture (by reducing idle).
2. (Its always a two step process if you change the idle) if you did change the idle do step 1 again without changing the idle speed by winding the mixture screw in until a slight drop in revs is noticed, then wind it out until it runs smooth.
Is this the method you used when setting the carby. Its best to reset after a carby build a few thousand kays after cos of all the new parts etc.
