Motorcycle Repair: Having carb problems on 91 suzukigs500e, gas tanks, stock exhaust

Question
The question I have is about my 91 gs500e. First of all it fouls plugs out quickly. Secondly it bogs out unless over 6000 rpms.  No low end power until it is warm.  Runs great for a few miles, then bogs out again and quits. I need to know how to fix it. I would much appreciate the help if you could help.

Answer
Shawn,
sounds like it is running rich, have you tried
changing the air filter? Is the bike running
stock exhaust or has it been re-jetted?
Are the gas tanks vents open or is there
pressure when you open the cap?
Take a run with clean plugs and stop the engine
quickly, see what color the plugs are at the
problem rpm. Fuel too rich=black, too lean=whitish.
Have you had a compression check?
All cylinders should be close to same and
around 150 psi.
If none of this helps, I suspect an ignition unit
acting up. You would have to try a replacement
to be sure.