obviously there's no absolute answer to this but I bought a 743 without a working hour meter and now I have it replaced I would like to set it to a reasonable average for what it might have been originally. when I bought it I was told the meter was set to 0 when the hydraulic pump was rebuilt. It was about 38 hours when I got it but it runs continuously if the battery is connected. so it added a couple hundred since then but I now have it disconnected until I can fix the hydraulic pressure switch under the seat that I have read is what is supposed to run the meter when the engine is running and turn it off when it's not.