Controlling the source vibrations in internal combustion engines is a crucial approach to minimizing the vibration levels experienced by the driver. The driver's subjective perception of vibration is primarily dictated by the vehicle's low-frequency response (<100 Hz). In IC engines used in agricultural tractor applications, the primary sources of vibration include (a) first-order inertial force, (b) couples generated by rotating and reciprocating components such as the piston assembly, connecting rod, and crankshaft, and (c) in-cylinder combustion. In this study, an order ranking analysis was conducted on a single-cylinder, air-cooled, naturally aspirated tractor engine within the driver's operating range to identify the dominant contributors to source vibrations. The first-order inertial force was observed to be the dominant contributor to the engine's vibration levels. Subsequently, an attempt was made to mitigate the unbalanced forces by implementing counterweight-based balancing strategies. A comprehensive analytical formulation was developed to determine the required bob weights and counterweights to achieve 0%, 25%, and 50% reciprocating mass balancing. In doing so, the rotary mass of the crank mechanism was also reduced, effectively decreasing the resultant forces. The developed crankshafts were tested in three phases: (a) motoring without compression, (b) motoring with compression, and (c) combustion, to assess the contribution of each factor influencing the engine's vibration signature. The first-order vibration amplitudes were measured on the engine block across its six faces. A vibration reduction of 12-30% was observed across all faces compared to the baseline engine for the 50% reciprocating mass balancing scenario. Among all the test cases, the 50% reciprocating mass balancing scenario emerged as the most promising prospect for tractor-level implementation.