Would a loss of top end power and increasing vibration be symptoms of needing a carb sync? My Spirit 1100 doesn't seem to be running as well as it did earlier in the year. Mostly in the higher RPM ranges. Seems to shudder a bit and doesn't pull through the higher RPM's as well. Before it would pull hard right up to the rev limiter easily in the first 3 gears. There is a more pronounced vibration at idle as well as the higher RPM's. Nothing severe, but stronger than it was. Just wondered if the carbs being out of sync could cause this? I'll most likely sync them anyways but wanted to know if there is anything else I should check?