I appreciate the info, dirtydeed. Based upon your chart, I can see a couple of things: the 2601 engine is rated at 2800RPM while the 2650 is at 2500RPM. The 2650 also has more torque. Interestingly, my 2920 engine is also rated at 2800RPM, so I'm guessing it is a derivative of the 2601 engine. I...