I know people think their bike problem is the only problem in the world but Mine really is !! YAMAHA FAZER FZS 600 13,000 miles OK my problem is : Bike gets to 3000 rpm - 4000 rpm and starts to bog down (running rough, feels a bit vibratey ? If I open up the throttle more the bike pulls out of the bog but still feels vibratey If it is bogging in 3000 rpm and I apply 50% choke then it will clear ? Been getting worse for a while but a few weeks ago she rode like new then it started up again ? What I have done so far : Changed Plugs, oil + Filter, Air filter, fuel filter and put some Sea foam in the tank . I Would appreciate any ideas why this has happened and what I need to do to sort it out Because the bike normally runs really well Any more info required just let me know