Dale, side gapping a plug is about like converting to Splitfires (which are made by Autolite). Sometimes people don't see any advantage, but others do.
A friend of mine is a prototype machinist at the GM proving grounds over in Mesa, AZ. Some years back, a GM engineer went to him with a few sets of stock AC plugs and asked him to split the stock side electrode to emulate Splitfires. (He did this using a very thin slitting saw on a vertical mill.) My buddy told me that the engineer said they didn't see any performance advantage. Very interesting.
There are some stock plugs on the market today that have multi electrods - 2, 3, even 4 side ones. Notice that they all terminate just short of covering the center electrode (when viewing straight down on the plug's bottom). There's also a design that has two side electrodes going beside! the center electrode. Makes sense to me!
But, having said all that, I must emphasize that I feel this is a minor item - easy to do in anyone's garage. What really is important for Bonny twins is to get a decent high output ign. box. I can't say that enough.
A high output box would allow one to open up the plug gap for better combustion initiating. That box, and a high output coil (or two) would really help the Bonny twins make more power. Heck, it would even help lower emissions, but I'm not concerned with that, as bikes put out so little smog in the overall scheme of things.
