After I had the engine scanned last week I just started doing the math on my hours in the PCM. The numbers from each rpm segment do not add up to the total run time. Is this because the key was on and the engine wasn't running? I figured that would have left time in the lowest segment but maybe not.

Total 294.5
0-749 52.9
750-1499 29.0
15-2999 11.9
3-3499 11.8
35-3999 16.9
4-4499 13.8
45-4999 18.2
5-5499 2.7

157.2 is what I add all the segments up to. Also the hour meter in the engine bay shows like 315 or something like that.

On the scan, the total hours cannot be re-set. You can however, have the breakdowns re-set back to zero.
Explanation......If you buy a boat second hand and get the scan printout but then want to keep track of the hours/revs breakdown for YOUR use of the boat, the dealer can set all the individual readings back to zero. You could re-set everything after a major re-build or at the start of the boating season but the total hours will always read correctly.

I bought my Verados with a total of 200 hours each but the scan only gave me a breakdown for the most recent 115 hours. The previous owner had it re-set just for fun! (He was a pretty well healed guy and a little eccentric)!

RR

Ok sweet that makes sense. Thank you for the explanation. Wish I knew the other 135 hours of use but looks like the last 150 have been pretty easy

I went thru something like this when I bought my 04 47 Fountain. Motors scanned 110,112&113 hrs but the hour meter read 235ish, I thought seller wasn't being honest. Did a lot of research and found out total hours can not be reset. I did not know single rpm hours can be reset.
I was told sometime back that hour meter does not count time unless motors are running, must not be true.

The regular hour meters are generally hooked to the purple wire which is activated by the key in the "on" position.
It doesn't matter if the engine is running.

Correct, meters run with key in on position, motor doesn't have to be running. When I bought mine, the two meters were off 20hours or so, but SmartCraft was pretty close (+/- 2hrs or so). Come to find out, my Stbd hour meter can be sticky and sometimes not register time (key on, engine on, or whatever mode). So, I occasionally reach up behind it, tap it, jostle the connections, wait to hear the clicking again, and it works. I got my two hour meters back in synch in my driveway by leaving the Stbd key on for some time and letting that meter catch up. Previous owner must not have noticed or cared too much, me on the other hand, too anal not to get them synched.....

Many years ago, I had a mid (?) 70's Johnson. One of the first V6 200 hp's. First boat I ever owned with an hour meter fitted. I crawled under the dash into the bow one day to move some life jackets and knocked the wires off the back of the hour meter. Just push on spade terminals so I pushed the two wires back on firmly. Looked at my hour meter later that day and it was going backwards!

Standard OMC gauge at the time and apparently there were quite a few manufactured where you could reverse the wires and spin the meter backwards. Fast forward to the end of summer, minus 20-30 hours, reversed the wires back to the correct terminals and sold the boat. Never felt guilty, it was an accidental error and the buyer got a damn good boat very cheap anyway. (One in a billion chance he's reading this, it was a red and silver Flightcraft Gunrunner.........)

RR

Are you guys scanning your own motors (or taking it to a shop), and if so what scanner are you using.

I used a Rinda scan tool, very user friendly. Local guy had one and let me use it.