Motorcycle Repair: Virago Midnight Special 1983, lean mixture, strange background

Question
Hi Christopher;

I have a 1983 virago Midnight Special 750cc. It had starting problems. It has been fixed at 99% by buying a new battery but when rode, the bike has a strange background sound as if the motor is not clean or doesn't turn well. I also need to turn the gaz screw up for a couple of minutes until the engine warms up or else it dies. And when I ride it, seldom, it stop and go, as if the motor is suddenly short of gaz for a fraction of a second.  If I use the choke, it will turn of. I'll be greatful if you could give me any suggestion.
Again, my email is elh_kh@hotmail.com
Thanks a lot.

Khal

Answer
Hi Khal.

Since the XV series is a very reliable motor, I can only assume that there are a number of things that need attending that have been neglected.

1) Check the plugs.  Is the bike running rich, normal or lean mixture?  DO NOT ADJUST THE MIXTURE SCREWS.  The carbs may need cleaning or something could be loose within them.

2) Synchronize the carbs and make sure that the valves are adjusted correctly. Valve adjustment must be done with the engine stone cold.  The repair manual has the proceedures and specs for you to follow.

3) Check the fuel lines and fuel filter (if one is installed).  Replace them if needed.  There could be a blockage in the fuel system or varnish in the fuel from old fuel if the bike ever spent any time in seasonal or other storage.  you may need to reseal the tank, if that is the case, as well.

Start with those and let me know what you find.
Good luck and ride safe.
FALCON