I used a stud girdle on my Toro rider to keep harmonic vibrations from reducing my plug life. Whenever I was in the back 40 and hit the tall grass, I would use a 100 shot to pick up a little speed. The problem I ran into was high-frequency spark plug oscillations. The stud girdle did wonders for my plug life, and I didn’t need to change the heat range or gap!
Later, when the cutting blades needed sharpening on my BIG mower, I discovered that side bolting the main caps in my V-2 Tecumseh improved the time between
oil changes. I no longer needed to add chicken fat to the
oil for increased lubricity.
So as you can plainly see, cross-bolting has many and varied benefits for everyone, everywhere, all the time!