Re: virago running on one cylinder

If you are getting spark, does it miss at higher RPM also or just at idle? What does the plug look like that isn't firing after you run it for a while? Is it black and sooty or wet? If it fires above about 3000 RPM but misses below that or at idle, the most likely candidate is the TCI unit. There are two other possibilities, one is the float settings, the other is the pilot screw settings. Try checking the pilot screws first. Leave the rear carb alone, but turn the pilot screw in on the front carb until you get  a "soft seat". That means that you are starting to feel resistance. Don't screw it in hard or you might damage the seat and needle. Turn it back out (counter clockwise) to 2 1/2 turns and start the bike and see if you still have the miss at idle. You can adjust it one way or the other to get the best idle. Let us know................