I'll agree with that. I recently picked up a Balboa that was smoking like a chimney. I switched it out for Gianelli and the smoke is gone. I figured it was that because I use Motul 600 which is pretty smokeless.
Try cleaning your exhaust. I like to use MAP gas, burn it out and then tap out the carbon. On most Sachs exhaust, you can take off the rear cone and tap out the baffle.