In the 4+ years I have been riding this bike, I have never had it running properly, until now. It finally runs the way it should and it is almost like getting a new bike. It's exciting all over again. I thought I'd share in case it benefits someone else.
The initial problem was that I installed pod filters and put on exhaust with only 3" baffles. So I rebuilt the carbs with a rebuild kit and installed a 6 Sigma jet kit with a 150 main and put one spacer on the slide needles. I started at factory mixture of two turns out. The bike bike seemed to be running lean. Full choke to start and kept it on middle choke to ride. If I turned the choke off it would run, but not hold an idle. It fired intermittently on the left cylinder when cold, idled rough when cold and high idle when hot. So I tinkered with it turning it out and retesting. I didn't seem to get anywhere with it, so I essentially gave up and rode it like this for the last three years.
I took the carbs apart again last month to clean and inspect them. They stay very clean because I run Seafoam in the last tank of the season so it sits in the carbs over the winter. I reinstalled them and the bike ran the same. So I took them back out, bench synced them, adjusted the valves, new spark plugs, plug wires and caps. I put the carbs back in and it still ran the same.
I got so frustrated I thought about sending Drewpy a plane ticket to help me out. I couldn't afford that option, so I started reading around this and other forums and found several articles about bikes with similar situations being fixed by leaning the carbs out. I guess I never considered this options because the bike seemed to starve for gas. I turned the mix screws to 1.5 turns out and tested it out. I had to adjust the idle screw, but the bike runs fantastic. I still use full choke to start (although that may be out of habit and not necessity), but it runs great with no choke, idles beautifully and sounds awesome.
I saw quite a few others with similar issues, so hopefully this helps someone out.
So just a quick recap with the highlights . . .
Prior problems:
Intermittent fire on left cylinder
Rough idle when cold
High idle when hot
Backfiring
Bike setup:
Pod filters
3" baffles in otherwise open exhaust
150 main jet
1 spacer on slide needles
Adjuster screws at 1.5 turns out
Valves adjusted
Carbs bench synced
Purs like a kitten.