The Triumph 900 and 1200 series engines have two balance shafts, one to counteract the vertical component of vibration and one to counteract the horizontal component of vibration. The shafts are in front of and behind the crankshaft. My T100 is almost glass smooth considering the rigid mounting of the engine. However there is a very slight viberation at 3800 rpm; probably this is the resonant frequency of the chassis/engine combination. Therefore, it might be considered that one of the counterbalance shafts in your engine might be timed incorrectly, and not properly reducing the vibration, or perhaps adding to it. This would be an issue to discuss with your dealer for warranty correction if it is a mistimed shaft. There is also a gear lash adjuster screw on the right side of the engine (under the alternator cover) for removing the backlash of the counterbalance gears. This is also a critical adjustment best handled by the dealer. Hope this helps.....
Craig
