I have a '99 Yamaha C60TLRX that will bog down on acceleration at times, not always, but has been getting progressively worse over the past couple seasons. If I'm able to go immediately after launching without having to idle out it will not bog until after the engine is warmed up good and drop the throttle down to idle and try to go again. It is this way in neutral also, will not rev correctly. Usually able to get it back to normal if cut off engine for awhile. Always happens at the same point just past high idle speed. Have recently replaced fuel line from tank to engine, fuel pump and re-built carbs. Any help would be appreciated Thanks.