This was TooMany's baby, and he was very honest, pragmatic and stoic about the test results. I still like the mod. The theory is sound, and it just looks like it should work.Its too bad you two had no improvements.
But, for what its worth, now you know.
I'm not positive, but I think the between-the-carbs clutch cable routing was used on models with un-linked carbs, so that would be 1970-1975.
I don't even run my clutch cable under the tank. It is totally in free air. The only thing keeping it from flopping around is that I thread it under the spark plug wire. Been this way for years and years. I have a very easy clutch pull.
BTW, I finally ditched this color scheme...