[tabora]

Aside from non-ethonal gas and an oil change after the first 5 hours of use, is there anything else that is recommended for longevity?

Nice machine. Hope it holds up for you as long as my 40-year-old HR214 has for me. Follow the entire recommended maintenance schedule and keep the undersides clean and it'll be an excellent tool for the long term!

The HRX equivalent of my HR would be the HRX217HZA. Maybe someday when my HR214SMA is 50+. It was my first Honda of almost 20...

 

[tabora]

Honda went from an overhead cam engine to a pushrod design since I bought one in 2003. Seems like they went backwards.

The older design Honda engines (GX) are overhead valve (OHV) with pushrods. The newer design engines (GC & GS) are overhead cam (OHC) with a timing belt. I have both, but my GX engines have a LOT of hours on them with no issues, other than a ring job on the 1983 GXV120.

I'm still trying to wrap my head around a compression release in a 4 stroke engine.

It basically short-strokes the exhaust valve.

 

[tabora]

Looks like the new GCV200 in my K6 VKAA is OHV pushrod. Maybe older is better?

You are correct, the new GCV200 and the GCV170 have gone back to a pushrod design. All the other GCV engines use a timing belt with an overhead cam. I do believe that the pushrod design is better, avoiding the timing belt, but only time will tell!