Converting to a decent electronic ignition system is one of the best thing you can do for a X flow, in my view.
I fitted a Lumenition years ago and have had no issues with it.
Ignition prices are ridiculously cheap on these cars, it is worth replacing plug leads and caps if they look slightly tired.
Once the carb is set and in a good condition, you are only left with the occasional oil change to worry about.
I agee....the X flow is a tough little engine and apart from breathing problems which are easly rectified it was only the ignition or electrical system to the engine that was weak. A good after market electronic system will work wounders and leave you to Tinker with the rest.
Breathing problems....easily rectified.....would you care to expand on that?
Breathing problems? Reminds me of a time I navigated for a lad in a Mk1 Mexico. He liked to build his crossflow engines a little slack and so at the start of each stage, I had to jump out out of the car and tip the contents of the catch tank back into the oil tank. Car went like the clappers though.
Only other crossflow problems I can think of is the standard front pulleys tend to disintegrate, fit a steel one instead
Arwyn