I have a 1983 xs400 maxim and I'm about 250 lb but even at that weight and I'm 6 ft 10 I can hug the gas tank and tuck in tight to clip 115 ish I like 10,000 RPM but for some reason when I jetted it down it got more horsepower also I side gapped my plugs so that helps as well and took the front brake off every time being so I reduced a lot of weight as well with the airbox and exhaust and I'm about to take the secondary kickstand off to drop another 12 lb and put a shorter seat but it definitely sounds like your carbs trust me you're going to clean them and ungodly amount of times what it will seem like but just running fishing line high test preferably through all the little nooks and crannies and watch it come out the other end of the hole and I mean every crevice must be clean so it's going to need to be done a few times get used to it or buying your bike and go twice as fast
