I didn't take into account that this car has a Euro dist. I'm not sure how much total mechanical advance that particular dist has, but I'll assume it's pretty close to the amount the USA versions have?10' BTDC also for carb-fitted engines you mean? I noticed that if I advance timing even a bit more the problem of the engine hesitating when accelerating gets better. It also idles a bit better when I put it more advanced, as if the engine likes it that way: Is there any risk of having ignition timing advanced beyond 10'BTDC? Thanks for your input Mike
In the end what's most important is the amount of advance at full advance. I know that's kinda hard to measure that without a dial back timing light though. I don't think you'll hurt the engine by setting the initial advance to 10' BTDC. You'll know that it's advanced too far if the engine starts to ping, or rattle - has pre-ignition. Some have assessed the SOHC combustion chamber as being pretty inefficient causing the burn to be slow. If that's the case more ignition advance is needed. I suppose a dyno can tell you how much advance is best, but a total of 36' BTDC is pretty conservative - IMHO. If that much advance worries you - use premium gas. Back it off if it detonates.
Bad news, I don't think that mildly retarded ignition timing is causing your stumble though.