Just picked up my first non learner bike, a 94 VFR750. Very happy with it, but discovered that on part throttle (ie, holding speed at 100kph) it hesitates, with a slight 'power on, power off' shudder, the same as what you would expect if it was having fuel scavenging issues. The tank is full and my hand is steady...? Dirty carbs? Your thoughts please!