Well I will both agree & disagree with Dave, just to confuse everyone even more.
Yes, the side walls are too thin
Yes the rocker cover is difficult to keep sealed unless you go to the effort of changing the $ 4.00 gasket every time and do it up with a tension wrench.
And yes the old side valve engines were easier to do routine servicing on, till you had to do something like adjust valve lash on.
However comparing the old side bangers to modern OHV engines is totally irrevelant as they were much better built, in fact substaintally over engineered and were 10 times the price / Hp of modern engines ( adjusted for inflation )
The 8Hp on my 1966 Rover Rancher II cost $ 600 Aus when new, in 1966 the average weekly take home male pay including overtime & bonuses was $ 85 so there was good profit in making them.
We all convienentally forget about this about this when making comparisons and keep thinking a 1966 $ is the same as as 2015 $
So a real comparison would be between it and an 8Hp engine in the $ 3000 + range which of course is not the Courage series.
Otoh, the bucket dedign is a pleasure to work on, you can do full internal surgery with the engine in place in the mower so there is 2 hours saved over anything other than the new Hondas with the diagonal closure.
You can get at all cowel bolts easily, without having to hang off the rafters or remove fuel tanks to get at the back 2 horizontal bolts found on just about everything else with a gravity tank, so two minutes for any Courage / Command as compared to 15 + minutes for a lot of Inteks ( mower dependant )
The hang down oil filters are easy to change cleanly without having 50 little different catch pans to slip under the horizontal oil filter and still spend 10 minutes of uncharagable time cleaning up the spilt oil and another 10 extra minutes trying to undo an oil filter that only has 5 degrees of accessable rotation to work with .
Both Courage & Inteks seem to have the same occurance of internal failures so there is not much difference there except the Courage is easier to work on.
Both the Courage & Command have exactly the same design and the Command, with a higher quality & lower weight crank never has a bolt loosening problem so I would assume Kohler designed the Command, then found they needed a lot cheaper engine because owners were too cheap to pay for good quality engines so swapped out a few expensive items to make the Courage.