If you opt for the more costly spark advancing ignition like from C&H then yes you'll see some rpm gains. The less costly one will only save weight. You can remove the key in the shaft to allow you to reposition the flywheel and use green threadlock to hold it in place, in effect advancing the timming. The key only acts to hold the timming at the factory preset its the taper in the shaft the holds it there. If you can get or make with a protractor, a timming wheel, you can find the current timming, 25*-28* or so and rotate the flywheel conter-clockwise to 30*-35* you will see greater power from the motor. However, the farther you go the harder the starting the motor becomes so make small adjustments and use a good tach to fine tune your results.