I recently replaced my Sparx rec/reg as it blew up (figuratively), new carbs and new fuel lines. I put a Boyer rec/reg in, 6 volt coils and reset the valves since I had the tank and carbs off any how. The bike rode great for a couple hours, then started backfiring a out of the exhaust. Then an hour later or so I noticed it was also backfiring into the left carb a little. Finally it stalled out. It was hard to start again and would stall if the revs got below 4k or so. I checked the rec/reg after letting the bike sit over night, 14.5 volts at the battery till about 3,000 rpms. After that there was a voltage draw. Any ideas whats up? I was thinking I gapped my valves wrong (feeler gauges are still a bit of a mystery to me) but not sure what else it could be.