I own and am selling this great mower, my wife bought it new in 1987. Came to this forum in order to see what others had to say about it.
Have always changed the oil annually and kept blad balanced and sharpened. Cleaned air filter and gave it a new plug once in a while, always ran gas out at season end. Starts on 1st pull every spring, polycarbonate (I believe) base never rusts or breaks, hardly scratches.
Bought a new Honda HRX217 in 2012 to accommodate larger yard in new house. The HRX217 works well but Honda has gone on the cheap with it's current lineup. e.g. the motorcycle quality cables with precision adjusters on the HR173 have been replaced with plastic bolt ons, the older ones clips were brazed onto the chrome steel handle. The chrome handle has been replaced with black paint. Not that any of these differences materially impact the mowers new performance but my HR173 runs and looks nearly new after 26 years ! That said the HR173 cost $359 26 years ago, try adjusting that for inflation and see why they had to cut corners.
Enough time wasted but I just needed to set the record straight on older Honda mowers vs. what they are selling today.