I have a strange issue I have been having trouble resolving, and I am hoping for help from the experts here. I have a 2005 Vmax with about 8500 miles. It was well cared for, always garaged. It has developed a strange misfire over the last year or so, and it only shows up when it is over 80 degrees F or higher. When the weather is cool, it runs like a scalded cat. It always starts easily. No other issues at all, just a slight misfire (mostly at lower rpm), when throttle is first increased. Once the misfire happens (like a hiccup), it takes off and runs strong. What I have tried: replaced fuel lines, cleaned fuel tank, replaced fuel filter, pulled carburetors apart and cleaned them / adjusted fuel level in floats, balanced carbs, checked all electrical connections (and eliminated many of the quick disconnects), installed COPS (although I am running without resistor because when I installed them I didn't know it was advised). I have also put in fresh spark plugs. Voltage appears good when I check it, usually over 13.7v even at idle. It is hard to describe, but it almost feels like it is getting too much fuel or not quite enough spark at lower rpm when I first hit the throttle. It is a quick hiccup/misfire and then it takes off and runs strong to redline. This hiccup can happen at higher rpm also, I have noticed it even at 4,000 rpm when cruising along and then jabbing the gas.