Motorcycle Repair: 1991 VFR400 mid-range problem., filter hoses, tap air

Question
The bike starts well and runs smoothly up to 5-6000rpm at which point it starts boggin out.Opening the throttle slowly can coax it past this point and at 9000rpm it clears and revs as it should.Once the revs drop below 9000rpm it starts bogging again.It behaves like its getting too much air,I`ve checked the fuel tap,air filter,hoses,plugs and leads.I haven`t checked the carbs yet cos I don`t want 2 strip them down unless I have 2.Thanks for takin the time 2 deal with this problem & I hope you can offer me a solution 2 it.

Answer
Timsk, my experience is on older hondas but it sounds like a carb fuel delivery problem.  It sounds like the bike is leaning out.  If you apply a little choke, I think you will find it helps which will be a confirmation it's running lean.

Regards
Rich