Hi. I have two 1vsh's, both rated to 1060rpm max. They did a version of this engine rated to 1500 rpm and, I'm told, the only difference is that the slower revving units have a "bolt" through the governor weights to increase weight and slow the engine. I looked in one of my engines and it has the holes on the weights but no bolts, which doesn't rally with what I've been told. Has anyone looked in a 1500 rpm version, or even ever seen one.. I know someone who added the bolts to a 1500 rpm VTH twin to reduce the max rpm.. Thanks.