Tom,
I'd go with the Husq hour meter for 17.95 and wire it into the run circuit rather than the key on circuit. Way too many hours are logged with no more than key on.
The first link is probably the one you're looking at. The second is a "genuine" Hustler hour meter at $39 bucks. Would take less time to just plug and play, but then, it is playing when you're not plugged in. lol
Max
https://www.ebay.com/i/132168311658?chn=ps
https://www.ebay.com/itm/New-Genuin...987651&hash=item3d42fb84b6:g:OJkAAOSwGrFZf0IM
If you want a set up with less phantom hours the best way is to take a feed off the alternator AC with a diode so you only record the running hours of the engine.
The easiest way is to take a feed off the PTO so you actually record cutting hours which will be a little less than running hours.
When it is all said & done, servicing by the hours on the meter is not an exact science so running hours will work just fine.
I try to get the residential customers to do a service at the end of each season regardless of the metered hours, it actually works a lot better.
Commercial customers get done twice annually, for most of them that is a bit over scheduled services , but commercial customers do things like check oil & grease spindles between services where as resedentials rarely do anything between scheduled services.When it come to resale time what is on the meter should be a guide not a determining factor.
Just finishing a mower that has been sitting out in the weather all its life.
500 hours on the clock so the motor should be fine but every bush & bearing plus 1/2 the control shafts needed replacing and the deck is swiss cheese.
The Troybuilt pony should be good for 1000 hrs + but if this one makes it to 600 the owners will be lucky.