I just bought a string trimmer with a 4 stroke engine. Reading the
owner's manual told me that it requires an inspection of the rocker
clearances every 25 hours. The process requires a feeler gauge, which
I don't have, and a torque wrench of some sort to reassemble the
engine cover.

While I'm sure I can perform this maintenance, I'm a bit irked that
these tasks are required for this simple device. I've never had to do
this stuff for the 4-stroke lawn mower engines that I've owned, so I'm
thinking that this trimmer is poorly designed in some fashion that
requires periodic disassembly.

Are ALL four stroke engines of this size going to require me to do
these inspections, or did I just buy an inferior model? (Troy-Bilt)