I HAVE HAD THIS 750-F FOR 27 YEARS LOVE IT. BUT IT DID SET UP FOR A WHILE AND NOW HAVE CARBURETOR PROBLEMS. HAVE HAD THE BIKE WORKED ON. BUT STILL HAVE PROBLEM. IT RUNS FINE AT LOW R.P.MS. BUT POWER CUTS OUT AT 4,500 R.P.MS.I KNOW CARBS ARE NOT TOGETHER AT HIGH R.P.MS. BUT RUN PERFECT AT LOW R.P.MS. DOES ANY ONE HAVE AN IDEAL. I HAVE SPENT MONEY ON THE SILVER BULLET BUT STILL HAVE CARB. PROBLEMS.