The 250 Recon doesn't have a balancer but does have flexible engine mounts. It still vibrates a bit. The old way of getting single cylinder engines not to shake was with the counerbalanced crankshaft, always a compromise as some of the up and down shake was replaced by forward and backwards vibration. A two stroke twin with separate crankcases is fairly well balanced as one piston is going up as the other goes down, do any motorcycles have them these days?

 

Good point with twin cylinders being self balanced in their design, there is a counterbalancer in the LT250R engine as pictured below (red arrow points at balancer drive gear the balancer itself is on the other side of the case). Maybe I need to just focus on engine mounts and not worry about the balanced engine.