Im bumping this as I got out today and tested my ported BS29 carb slide.
Basically, purchased a new throttle slide / piston valve for the CV carb from India and then increased the 2 vacuum ports from 1/16 to 1/8 inch. The Electra is very punchy and responsive! Im liking it. I could only go through the first 3 gears (riding in 38 degrees), and so far I like. I just followed the instructions on the web site and i contacted the author for the slide. Cost about 11 US dollars + shipping.
Should also say, im using a K&N + free flow exhaust system, w/ 17.5 pilot and 115 main. Needle in the middle clip with 1 shim. May change the needle once it gets warmer.