bike boggs down between 0-5000ish rpm then it runs smooth after 5000, any ideas what is causing this?

 

the idle and/or pilot circuits of the carbs are dirty/plugged or the spark plugs are getting old.

 

pilot circuits??

 

dirty airfilter? go stock

 

Don't let it drop below 5000?? No it sounds like it could do with a good service, new air filter clean sparks, sync carbs etc

 

if you pull the choke lever on a little does the running problem go away or get worse...? If it gets better the carbs are dirty.

Fuel from the carbs is delivered by 1 of three "circuits" or paths. idle and just off idle is handle by the "idle" circuit.Then light throttle is the "pilot" circuit...mediumto full throttledelivers fuel through the "main jet/needle" circuit.. The passageways in the first two of theseare pretty small, and can plug up.

There are various topics in here on cleaning carbs yourself...good luck

 

Also replace fuel filter