6 hp BS on an Ariens mower. Can I adjust the RPM?

[JimJamie]

I have a fixed RPM mower. The rpm's seem lower than they used to be, and it is not sending the cut grass into the rear bag as well as it used to.
I just sharpened the blade, and it made no difference.
Can I increase the RPM?
I'm fairly handy with motors, so if I thought I could, I'd give it a shot.

 

[ILENGINE]

It can be done, but it is best to use a tachometer to set the speed properly. engine rpm can vary depending on blade length, 19,000 is considered the top blade tip speed and still be safe. Above that can cause wobble, and blade cracking supposedly.